If you flash a different kernel than the stock kernel it will break the camera and maybe a few other things but it would help in the 100% brightness issue.
I would not recommend trying a different kernel but if you want try a sense kernel but nandroid first
If you didn't follow the directions for partitioning your sd card as instructed, then yes that sounds about right.
I didn't partition my sd card either and I have around 200 mb left so...........
For future reference, for people wanting to try B3 from Virus, it is not necessarily needed to partition the sd card to try the the rom. Download and flash but be warned, if you have a lot of apps, you may run out of space

The rom is pretty big