I'm really enjoying JD's Kernel:
[KERNEL] JDkernel Tuna v1.1.2 UPDATED 12/29/11 - RootzWiki
In SetCPU set the governor to Interactive, then forget about it. It runs really really smooth, handles 3D games better than other kernels I've tested, and battery life is great. I undervolted it a bit based on a bunch of suggestions I saw, but really if you're not comfortable you shouldn't stress it. It comes undervolted a bit out of the box and if you like the battery life you get with it, you won't get a sick amount more by undervolting.
Regarding root... I got the Bionic on launch day it was my first android phone. Thought all the rooting and stuff wasn't for me, never thought I would try it. I eventually gave in and rooted about 2-3 weeks in, lol, because I wanted to freeze the bloat on it. Within a week I was flashing ROMs, and within a few months I realized I need the nexus for the unlockable bootloader and all the dev support that would be available. I unlocked and rooted my nex within 2 minutes of getting home with it