any kind of MOD done improperly will screw up your system. Personaly i think all the pretty lights are stupid. Are a few lights in the front (or sides or wherever) going to make your computer run any better or make you any more 1337? NOPE!!!!!!!!!!!!!!. as long as your power supply is big enough to handle everything you have running ( if i have to explain how you figure that out you should go buy a HP) then they shouldnt be a problem.

P.S. What the hell does your number of posts have to do with anything related to this thread?