#2
It isn't a big change at all, so there should be very little warping. You might want to think about the setup of your bridge though, and if you have to change that, then I'd advise looking at your neck bow as well.
#3
Yup, your neck will become a corkscrew. Its hopeless......



Its fine, 9's to 10's shouldn't need a truss rod adjustment. Only thing you'll need to do is set your intonation probably.
2003 Music Man Axis Pacific Blue Burst