I'm not so sure if I'd like them to buy Remedy, I mean I would but at the same time I'd be worried MS forces them to pump out the same game every other year like they seem to do with a lot of their studios, on the other hand if they bought out Remedy they could expand the studio and release games in a quicker fashion, or maybe even have two teams in remedy working on separate games. I don't really trust MS to give Remedy the freedom Naughty Dog has, which imo they have earned and deserve.
To your other question, I think QB will sell well. It seems to be appearing to the masses more than Alan Wake especially in a world dominated by superhero tv and movies, and AW went up against a Rockstar game (What a terrible decision). Plus, it's MS, with how they have been advertising this gen, at least in the UK, I expect to see Quantum break advertised the fuck out of which should help and the word of mouth seems good around it.