I feel like pretty much all the stuff I want could be added in 2 expansion packs: one castle/fantasy themed, and another focused on more typically masculine activities.
The fantasy castle pack would add spiral staircases and all the other architecture that should have been in the castle kit, also a drawbridge and castle style furniture, tapestries, knight armours, swords and shields to put on walls, and fitting clothing. Generally three styles would be added for clothing and furniture: Medieval, colonial and steampunk. The steampunk stuff would include steampunk variants of all electronic stuff, even a new phone skin and background.
Steampunk robots could be build as a new life state similar to the one from university, but better and you can change the appearance. They are shaped similar enough to humans to be able to wear clothes, but can be naked. They can become more human too.
Fey would also be included, which can become like fairies but those wings have to be earned. They can also have horns and goat legs, being more like satyrs, they would have some options unique to them and can learn some fey magic. Fey magic would practically be a fourth category of magic, functioning similar to the realm of magic schools and a teacher could even walk around there if you have both installed. It could add some new alchemy options as well.
The masculine activities expansion would I guess be more hobby themed. Not exclusive to men of course but it would heavily focus on hobbies popular with men since the game is lacking that. It would also add lots of clothing for men and for just once, less for women. Just regular clothes that the average guy wears, hairstyles and some facial hair options too, some cool tattoos, various sunglasses.
Cars would be added, including several different options to fix up themselves, including an old timer. Would be some customisation possible here with different wheels, spoilers, bumpers, tinted windows and such. Could really make them your own.
Bought cars could also be customised a bit like that, but the ones you have to build can't be bought so it's worth the effort.
several bikes would also be included, including a chopper you can fix up like the cars. You can also select the helmet your sim wears when riding their bike. (Could maybe risk getting a ticket if they ride without a helmet.)
Pool tables would also be included, as well as elevators and a fireman pole. Climbing up the pole could be something a sim with high athletics could do. Rope climbing could also be a new activity.
Wood working would also become a new skill, a new tree would be added that sims can chop up for firewood or to use to build various wooden objects with in styles you can't buy. Sims could even build a shed with it or a tree house.
Several sports would also be included that Sims can now play at home: Baseball, ice hockey and the return of sim-fu. Baseball and ice Hockey would also have new sport careers to go with them, and sims can compete in Sim-Fu tournaments at a new Dojo building.
More video games are added as well. Sims can now play Mass Effect, Command & Conquer, Dragon Age and Star Wars: Battlefront. Shirts, caps, posters and such to match would all be added too. You can now set a favourite video game for them as well that they will play most often and might desire to get merch from and talk specifically about.