I voted YES on flying creatures. Not just them little wannnabe flyers, the Cazadores, but real ones that actually fly high in the sky, and if they're hostile you gotta shoot 'em down, like Cliff Racers from Morrowind.
Cliff racers in Morrowind was the whole reason that I don't want flying enemies in. At least not until a better engine can be used to utilise it.
No to giant bullet sponges as well. I'd rather have enemies which were more tactical and tried to avoid getting shot rather than ones who could be filled with enough lead to make a replica statue of themselves.
Not a fan of expansions unless they're free. I'd prefer that I got them with the initial release rather than having to fork out more cash for them or wait for the GOTY (assuming one is coming.).
I personally couldn't care less about houses, so I would say 1, but it doesn't matter to me if there were an infinite amount, or none at all.
To repeat what I said about DLC's I'd prefere there be none, rather I get the whole package in one go as opposed to having to spend extra on some added content that I really shouldn't have to had payed 800 MS points for (well, except perhaps Point Lookout.) or waited for the GOTY.