[Help] Packs for my Playstyle

I recommend you getting the following packs:

1. Island Living for the Sulani world & Mermaids
2. Horse Ranch for Unicorns & Chestnut Ridge World
3. Cats & Dogs for Spellcaster Companions & Brindleton Bay World
4. Get Together for Windenburg World & Ruins
5. Strangerville will go perfectly with your Get to Work pack
6. Get Famous has great multi theme costumes & objects that will go perfectly with fantasy play
7. Lovestruck has even more multi theme costumes, beautiful walls & object

Don't get Business & Hobbies pack, it's broken right now.

I second this. Island living for the Mermaids, cats and dogs, and Get together for sure. The rest of the suggestions are also good.

Your play-style is very different from mine, but I will still add my two cents and hopefully you can use it for something. 

• Get together's biggest feature is the clubs, and even if you don't like partying/social gameplay the clubs are extremely useful in making the game come alive the way you want it to. You can make clubs for skill building, or for occupying certain spaces. If you have built a lot with objects that won't get used normally (say a pool in a park, or playground in a library...) you can make clubs with the purpose to use them. The world will then seem more lively when your sim visit it and sims will behave like you want them to, rather than what the game wants them to. That, together with the best world in game, is enough to by the pack in my book. 
• Island Living is in my mind a great pack, and I know people complain about mermaids but I think it's what you make of them. They can change the weather, be mean or good, make people drown and sleep in the water. The downside is that they can't live "in" the water, but there are ways around that if you are creative enough. Since you like occult gameplay it feels strange not to get this one. 
• Get famous has great BB for futuristic or historic gameplay but the world is (in my view) limited and yes the reaction to fame annoying. However, you can opt out of fame if you do not want the feature, which is good, and since you said you don't mind playing with mods there are several that cubs annoying behaviours from the pack. Getting the acting skill will unlock features such as cry on demand which is sometimes useful. 
• Cats and Dogs are fun to play with but yes they are overpowering and needs lots of attention - however - there are mods that tone that down. Brindleton Bay is beautiful and quite large. 
• Horse ranch has a lot of good clothing for historical gameplay, and the world is okay, but I am not sure if those features are enough to warrant getting it if you don't want horses in your game. The mini sheep and goats are cute but not that much fun. If you do want unicorns, however, you can at least make horses seem like unicorns even if it's only skin deep. 
• I'm not sure what Lovestruck would bring your style of gameplay to be honest. 

Other packs that might work for your style (I'm assuming you have the occult packs): 

• Crystal Creation - would work well with skill building and retail. 
• Journey to Batuu - for the BB which works well for futuristic or historic gameplay

Lovestruck

Your mileage may vary, but I must admit I disabled this one in my game. When playing with an intentionally single Sim, I found the daily pop-ups trying to get them to date someone extremely annoying.

Horse Ranch

Farm hands are definitely useful, if occasionally buggy. I love the idea of nectar making, but don't use it as often as I thought I would because the skill increases so slowly. But for me, the best part of this pack is the goats and the grocery store (a rabbit hole building) - do you play with the Simple Living lot challenge? I do most of the time, and goats are way easier (and take less space) than cows, plus having another option to get groceries besides the Henford on Bagley stand or delivery is welcome.

Cats & Dogs

I have always found the cats really easy to take care of, though I know that's not universal. I love giving my households pets, in part because they're cute and in part because you can raise social/fun by interacting with the pet instead of needing to go socialize with other sims. With Realm of Magic, you can also make your pet into your familiar.

I will say that if you get a dog, you should either make them lazy (don't want a lot of walks) or independent (can be sent to walk themselves) because in most worlds the walk-the-dog action takes far too long.

Get Famous

Famous Sims can get annoying showing up where they don't even make sense. It's a fun pack? But yes, a bit overpowering.

Get Together

Sounds like you've already identified that you're not interested in the game play. It's up to you if the world & build/buy are worth it to you.

Island Living

I wouldn't buy this for the mermaids. But I absolutely love the CAS, build/buy, world, and conservationist career game play (though the last is a bit buggy at the moment). Not sure the pack is really right for your play style though.

Business & Hobbies

I honestly haven't used Get to Work since Business & Hobbies came out. I love the different custom home businesses you can set up. The retail is admittedly limited, but if you like self-employment skill careers this seems right up your alley. For example, you can have a painter teach painting and sell paintings, or even essentially rent studio space if you set the business activity to painting, set up a bunch of easels, and charge an entry fee.

My playstyle sounds similar to yours, with the difference that I do like to add children into the mix.

I would recommend

• get together: this pack has great assets if you like to create historical buildings The world is big and beautiful in my opinion. The club feature has nothing to do with clubbing. It allows to manage groups of up to 8 sims to easily get together and focus on certain activities. I use this feature a lot in my game to the point where it is a must have.
• Strangerville: if you like aliens, you might like this one as well. It has a quircky story to play through, very different from other packs. If you get this,  I would recomment taking your time and play through this story at a slow pace to integrate your own story.
• Businesses and hobbies: if you like to run a business, then you will like this pack. You can basically set up your own community lot to own and manage as a business. The stores work a bit different from the ones from get to work. They are perfect for selling crafted good but if I want stores to visit as a customer, I prefer get to work.

To consider for a side feature?

• Island living: mermaids are lackluster but I still enjoy having them in the game. The look awesome and the world is very beautiful to live in.
• Discover University: The most overlooked occult of all comes with this pack: servos. You need to level up the robotics skill and can create some robots to help with practical tasks as well. So perhaps on a sale to get servos in your game. The univesity gameplay can be ignored if you don't like that aspect.
• Batuu: the gameplay is very limited and confined to the vacation world but you might enjoy some of the build buy for sci fi builds and some of the CAS for fantasy stories.

Other packs you mentioned

• horse ranch: the possibilities in this pack are rather limited but if you enjoy cottage living, then you might like this pack as well. Sheep and goats are cute alternatives to llamas and cows without being tied to a shed. Nectar making is fun as well and the horses are fun to play with. Unicorns are unfortunately make believe but can be nice to play pretend in combination with spellcasters and fairies
• cats and dogs: you won't get anything besides cats and dogs. I hardly ever use them but it is a nice option to add to the family if you care about them
• get famous: I bought this pack for the CAS and build buy assest. It is possible to turn off fame so you can avoid it. Some sims come with fame. I usually use mccc to force them to leave the lot or remove their fame in their own household. If you don't play with fame, I would suggest getting this on a sale.
• lovestruck: I decided to skip this pack because the task to keep up romantic satisfaction which will go down on all families even if you don't play them.

I couldn't be without my Island Living, I don't do much with Mermaids though. I only have one. But I love to be able to "shipwreck" a Sim with nothing to their name, in raggy clothes (depending on owned content but Werewolves has some good ones) on a deserted island in Mua Pel'am, near the volcano. They learn to fish and harvest plants to survive, as they build fitness skill they can learn to Scuba Dive for treasure. They beachcomb to find shells and surprises and shower in a waterfall. They cook food on a BBQ or in a firepit. Eventually once they've earned enough money by planting a little island garden to harvest plants and selling the fish they've caught, they'll build their own house somewhere and the island waits for it's next Sim to "wash up" on the shore. I often combine it with the Making Money Scenario, angling, collecting, money and gardening aspirations and rake in those reward points. I get them to chat to a few islanders and dolphins for the loneliness but then the calls might start so the phone goes on silent! It helps to give them the Independent reward trait or Needs No one trait but that costs a bit more, you could also make them a Loner in CAS 🏝️.

Horses were my favourite addition to the game with Horse Ranch and I love to run a ranch. Personally I find the horses slightly lower maintenance than other pets and I love the mini goats and sheep. They have loads of personality for me. I like to combine it with Cottage Living to have a proper farm. It takes work but I usually give my Sims a lot of reward traits to make life easier, like Steel Bladder, Hardly Hungry, Seldom Sleepy, Antiseptic and Carefree. But there is a current bug with some players reporting animals ageing up and dying so I'd maybe hold off until that's fixed. I don't know if my game is affected again but I'm avoiding my farms and ranches for now just incase 🐐.

UPDATE:

Since the Summer Sale is up I am starting to lock in on decisions (probably going to split my purchases into two, one sooner rather than later and the other closer to Enchanted by Nature release date).

I decided to go a little out of my comfort zone and try Get Together since the feedback on clubs seems intriguing and Lovestruck (with the potential of getting a no romantic satisfaction decay mod) just to add social and relationship complexity to the game which at the moment without seems flat.

Horse Ranch is another one I think I am going to get—based on feedback and features.

Cats & Dogs and Get Famous are still in the maybe pile still might get before sale ends.

Island Living and Business & Hobbies seems to have gotten a lot positive feedback and heavily looking into. Slightly wavering on the "bugs" in Business & Hobbies and how much I will use Island Living as for Sims 3 I didn't use Island Paradise as much as I thought I would, but the "shipwrecked" scenario does seem like it be fun to try.

Thank you so much for the feedback and opinions so far! I had done a lot of searches and research before I posted this (and still am) but just was worried my playstyle isn't the average playstyle so reassurances were/are very appreciated!

HollownessDevour​ I’d add my vote to Horse Ranch. The world is great, lots of playable areas and nature. I don’t play with horses either but I love farm/ranch life (it goes REALLY well with Cottage Living) and mini sheep and goats make it into most of my gameplay (they’re also easier to care for than dogs, and can make you ingredients or simoleans, depending on your gameplay). You can also make a lot of money or find things to sell by harvesting prairie grass, which is all over the world and also in Build/Buy for you to add to your existing lots. Though Build/Buy is more rustic than Cats and Dogs I prefer the quality of the items in the newer packs, and use a lot of Horse Ranch in a wide variety of builds.