^so you want the lights on the buttons off but the screen on ? for that you need to root your phone and install a mod that allows you do to that(if available for your phone)but your battery wont last more than a hour with the screen continuously on.
and if you think you are going to break your power button then again you can root your phone and install a volume button wake mod that allows you to use your volume button to wake up the phone.
don't forget is my Volume button wake up mod ....
@OP... you have two options..
without Root:
install widget locker 2.1.. you have to sacrifice your sense lock screen. in widget locker application you can set it to wakeup screen with volume buttons
with root: if your mobile is not in warranty, unlock bootloader and install my mod for wake up screen with volume buttons...
with root you won't have to sacrifice your sense lock screen...
For locking the screen install Screen locker widget from android market... this combined will spare your power button fully...