Thanks, Turducken.If you've installed a Custom Recovery then yes it should work. Without one you can't flash a new kernel.
P.S. It's the stock ROM that's unstable!
I suggest you read ALOT before diving in. You can brick your phone if you go in half cocked.
I'm looking for ROM that focus on battery life. I don't want my phone to die in the middle of the day.It comes down to personal preference. Some are bare bones and focus on battery life. Others are feature rich.
I suggest you try a few and see for yourself. I personally like the "build your own" philosophy with devoid roms but some think they're a bit hardcore.