what unixpsycho said. i would check out Geek For Me – Android CDMA Sprint Hero for info on rooting, they have a great app to root it for you, and their ROM is pretty good as well
Rooting will not change a thing other than what you tell it to. You can flash roms that remove Sense, in fact that is what I am currently running and absolutely love. I don't miss a thing from Sense and the speed boost is very nice.