Thanks for the advice, everyone. I think I may give the string height a little more time since I just got the guitar Tuesday... I'm so used to playing the ibanez and between the higher action and larger frets (medium jumbo), I just need time to adjust.
As for the humming, I talked to someone who's worked on fenders for years and he tells me that the pick ups on the early 2000 MIM strats are pretty poor - not much better than the current squire pickups. I guess I'll pick up some noiseless single coils first and get a seymour-duncan humbucker later. When I get the new single coils installed, I'll have the guy make sure there isn't a bad ground/wiring, too.