1. more age groups (babies and teenagers for example) would help make the cities look a little less empty
Nods to Holycannoli, yes, that is a good mod that shows the potential of it in game. I don't think it would be a bad idea at all and would like to see kids become a bigger part of the world then they are now..
2. theater guild/traveling company of actors (could perform in towns and in castles) would mean more things to do in towns and a chance for TES to show off its ridiculously extensive lore
It would be a nice touch. I would actually like to see an option to becoming a patron of a theater (or something else) or something of that nature (part of my "Moneybag DLC" wish).
But I had never thought of an actors guild or something of that nature. I think there could be some real potential there - of course there are a number of factions/guilds I'd like to see pop up at some point (Vampires, Forsworn, Necromancers, East Empire Company, Thalmor...) but theater guild - yeah, I really like that idea.
3. more interactions with spouses (a hug or a kiss animation, possibly? or more dialogue options)
Definitely more dialogue options.
4. more houses (either by adding versions of already available houses in terms of price range/quality or by adding more houses in towns that don't currently offer permanent housing)
I'm not personally to interested in more houses. I'd like more upgrades or something with the existing ones (maybe contract a guild to make an upgrade based on character play style - get the mages or thieves to come and add something special).
Personally I'd like to see something "next step up-ish" if you get to a point where you have the money in game for it - a castle/boat/fortress (with associated quests, upgrade options and the like). Or let us build/rebuild a town. Helgen needs some TLC. Or even a farm.
5. garden/water plants indoors and outdoors
I liked the option of this since Morrowind. It seems like something my Televanni mage character would do - have a garden of herbs and alchemical plants. But decoration options are nice.
6. clothier (similar to smithing (and will have its own animation)) with a larger variety of clothes available for creation
Not sure, initially I'd just like more clothes, But it could be interesting.
7. added animations that already exist for npcs (like eating and playing instruments) for the player
Would be good.
8. better "pet" system (by which I mean a more stable way of keeping dogs at home)
Yes, and more pet options. It doesn't even have to be something I'd take with me adventuring.
10. a non fast-travel option for carriage rides. (I really enjoyed the carriage ride that occurs at the beginning of the game and always thought it would be nice to experience something similar again)
That would be nice indeed.
feel free to write your own ideas or comment on the ones I posted here in the op.
obviously skyrim is a pretty great game without any mods or dlcs but gamers inherently are insatiable beasts, so..
Agreed, it is a great game.
I have some of my "wouldn't it be cool" wishes in my sig. I'd like a couple more factions (or as many as Bethesda want to give us, I wont say no to many) - I mentioned some here already.
Would love some more vampire content (quests, factions etc). Would love giant content - they are intelligent (but primitive), I'd like to befriend them, help them, protect them, anything. If you have quests giants I would like to do them for you (I've learned the dragons language - a bit - I'm sure I could learn giant). Anything more with the Forsworn (especially being on their side) I would love.
Stuff for money at high levels (of wealth) - mentioned some here. Things to buy, things to improve (guilds/cities you have a stake in for example), things to sponsor or become a patron of (like the orphanage or a theater - our money/decisions making it better or worse).
Yes, such a great game, and with so much potential for things yet to come!