Out of curiosity, what's the difference between your two Live accounts?
I3L00DFUMBLE is my main account. The guys that I play with that have 'I3L00D' in their name are friends of mine that I can play with and know they won't act juvenile.
WalkingFumble is the tag ive used since SOCOM on PS2. I use it when I want to play with you guys to not be bugged by my other friends, and to boost my main account (for achievements, not ranks).