I wouldn't add anything. If they did add the things you stated in the first post, it would be like Harvest Moon with animal villagers. That's what I think, anyways.
If not the ability to choose where villagers homes go, then to at least approve of it. Like when Isabelle says, "Is this about where you want it to go? Here's an idea of what it will look like..." She could do the same on the morning of when a new villager is moving in. "This is where your new villager wants to move. Is this acceptable, or should they relocate?"
OR.
That is a happy little bag of grass seeds. The cost for that item is 1500 bells. Are you gonna buy it?
I want to add an item, since we cannot be villagers ourselves and I wanting to pick a wolf I would add in a wolf headband accesory and a wolf tail accesory that go together as a pair. And if anyone else liked this idea they could have cats,dogs,wolves,deer, any animal with a tail and ears basically if others thought this as a good idea. And it'd be adorable
You could also only wear ears or a tail or both it would be like fruit, merging the two items would make them one so you can wear both at once but having them seperate you could wear them seperate.
If only we had good modders for animal crossing that would be amazing...