Graphics
If we're talking a sequel, I can only imagine the graphics would improve down the road. Part of that would involve advances in the medium itself (better techniques and software), and hardware getting better (which it probably will).
Of course, if the sequel is a different genre or style of gameplay (a few series do this), and they don't use a voxel based system, they'd be more so limited by their artists.
More People
I'm pretty sure those are coming. NPCs besides traders seem like they would be integral to the story they plan to implement. Even the backstory in Madmole's recent video for one of the houses would be better cemented if it had somebody in game to represent it. Whether that be someone effected by it to reference it, or the presence killer themself.
As for creating a band and making a small settlement, that would be awesome. I don't know if they have much planned for that or not, or what they might have planned. It's been mentioned in patch notes (Alpha 16 mentions settlements in some changes to land claims), so hopefully we might get something. But if it doesn't make it into this game, it'd be a great idea in the next.
Perhaps the sequel itself could be about managing a community and building a society from the survivors and ruins. It could be either a prequel or a sequal, as it could cover the rise of the White River Settlement, or be about a new / greater community that's the progeny of our efforts in this game.
Storyline
A story is coming. I'm hoping it's multi-faceted, and not overly linear. Madmole has talked about concepts for the White River Settlement and The Duke so far, and they seem to be the center of the story. I'm curious if other smaller factions (like the Crazy Jake Clan, which is just referenced for now) are going to be present in the final cut.
The current quests I'm assuming are a placeholder, and just to get the system in place.
Realism
Some of those ideas are interesting, others not so much.
I think food management could really add to this game, and I would like if there were more variety to food and possible buffs to more difficult and complex recipes.
As per clothing, I think if maybe what you wore could have an impact on things you do could be neat. Like wearing a suit would be great for social interaction, but not be great for physical activity.
I don't, however, really find the idea of cleaning clothes to be interesting. It doesn't add a meaningful mechanic, and is just a chore.
I feel simlarly about sleep, since days are relatively lengthy and the game is in realtime. Maybe for NPCs, but having the player leave the game running and do nothing isn't fun. Having time skip would trivialize surviving through the night, and be difficult to implement in multiplayer.
Character Customization
Some more customization would be nice, but not heavily necessary IMO. I do like the idea of tatooes though.
As for console, I don't really have any comments.
Farming
For the current game I think the farming we have now is mostly fine, however I kind of wish plants needed water for a little bit of upkeep, but don't want anymore than that.
Of course, farming in the next game, depending on the idea and scope of it, might benefit greatly from more in depth farming.
RE : Discussing Potential Sequels
Personally I think it is appropriate, since TFP have mentioned that they are in the final stretch and are locking down on features.
That being said, I think it is important to keep in mind that there may be post-release content and that a sequel is quite a ways into the future. They also haven't really said anything about it, so it's highly speculative as to what the next game could be. Madmole has mentioned that the next game they make may not even be a sequel to 7 Days to Die, nonetheless one similar to what we're playing now.