Curses... lot my long as heck post... ah, time to retype.
About making the hospital, science lab, and police station visible on the world maps? I don't think that is necessary and would be quite a hassle for the EA team. Rather, I think a good alternative is to have the ability to travel to the lots via your phone. Also, if your Sim is sick, a pop up option to be able to go to the hospital would be nice, like how it works when a pregnant Sim is in labor.
I'm totally down with the build/buy option being available without cheats. Of course you cannot change the lot type, but being able to edit the lot without hassle would be lovely. I could easily dismiss the Artic Fan animation, however. There are plenty of items in the game that would certainly be cooler if they had animations for their particular uses, but none of them really need them. So unless there is the idea to do a refresh on a lot more items in game, giving the Artic Fan an animation only would likely just get a lot of Simmers excited or up in arms about giving animations to other things like clocks.
The desire you have for Retail... I think the reason it lacks the upgrade and reward system is so the Doctor, Scientist and Detective careers could be more immersive, interactive and have more items.
For what you desire, it would have been better to make a whole Retail pack. It would be able to have the upgrade and reward system, but it would also be able to create more interesting stores. It could have different store types you could select. There would be a build/buy and CAS items that would allow you to make stores that don't rely so heavily on just base game items or other packs. That would have given the ability to make hair salons/barber shops where a Sim comes in, gives a description of a hair style they are looking for or ask you to select a style you think would suit them. Load into CAS and pick a new hairstyle for them, get feedback and get paid... unless they are so angry at what you did they decided to not pay you. Same could be done for cosmetics. A Sim comes in, wants help to find the right look for them and their personality or for a special event. You load into CAS and can create a look that you think suits them or the event they are going to. Again, you get their feedback, get paid... or get chewed out because you made them look horrible and the do not pay you. I so would have gone for a mechanic career to be added in. You could have a mechanic shop, build, fix or customize a car and gain skills from it. I wouldn't insist it be functional, but it would allow Simmers who like to build to add garages to houses and put their creations in said garage or driveway.
I don't know about the reputation system being added to careers. This may be due to my own experiences at work. You can have people who are horrible, but are excellent at their job. You can have people who everyone loves, but they slack off all the time.The active careers already allow you to fire or promote employees. The ones that aren't could likely give you a scenario, but how that would effect your reputation just feels too unnecessary and up to chance if you add in a reputation system. You fire a Sim for slacking, but then your reputation goes down because everyone was that Sims' friend so morale is lower. You fire a Sim for not getting along with their co-workers, but find that in firing that Sim has caused a huge gap in efficiency, so you have to make all your mediocre workers work harder and later than before to make up for the loss, so even thought he Sim they hated is gone moral has lowered due to the extra work, your reputation falls and you have to stay later for work. So... yeah.
I'm not touching the edits and additions to the Doctor and Detective careers. I have no idea how much would be needed to implement those things and if it would keep the pack a game pack.
Sixam & Aliens... It would be nice if the one lot there was editable without cheats, but the rest of the things listed...
Again, I say you'd need a separate Game pack for Aliens alone. GTW already has so much going on in it, adding all those things would be impossible.Sixam is an alien world that is not part of the Sims world. Therefore, it requires the ability to access it via a rocket or a Wormhole generator no matter what via Sims on "earth". Therefore, more reason there would need to be a pack. In that you'd get your power tree, your Alien could work up to get the ability to disguise themselves properly, learn abilities and the like. You'd have an actual with a map that would allow you to travel to residential and community lots. To get to the world all the other Sims live on, your Alien would need to build a flying saucer. The Sixam lot in GTW could then be considered just another small part of the planet, like how the hospital and police station are lots that are part of Magnolia Promenade and the Science Lab is a lot that is part of Oasis Springs