ok so i have seen this happen on a few evos from time to time. it looks like you have some bad blocks on your internal partition that is preventing you to do anything to the phone. basically this is a hardware issue. i have not seen much info on this but here are a few threads that might shed some light on it:
[Q] Root Trouble Caroline Failed - xda-developers. now i know this is for revolutionary, but it explains about what bad blocks are.
Anthrax Kernel for Evo 4G - Page 9. this is the post that one of the guys who posted in the first link was referring to.
unfortunately it has nothing to do with apps and memory. it has everything to do with your system partition on your phone. if you have bad blocks then there is not much you can do from what i have read.
sorry to be the bearer of bad news
however, if you do come across something that fixes bad blocks then please post it here.