re: Any negative for having too many CCs open?

Depends a lot on your current credit, but overall not a huge deal. If you're going to do it hurry up and do it now, otherwise wait till after. I would stay away from applying for anything a min. 6 months. I would hate to see you lose 10 points and pay thousands more in interest on your house.

Google App-O-Rama or AOR and you'll get some good insight on how to do it once the house is closed on and you don't have any other major applications coming up. You can bank some great rewards doing quick app sprees. I just did a 3 card AOR for some 15 month 0% offers/cash/cashback/airline miles.

If you fly American or USair its a good time to double up and score bonuses on both programs' credit cards before they merge the FF programs. Then you can combine those bonus miles for some big $ tickets.