S.E.P. - Somebody Else's Problem, popularized by the SEP field in Douglas Adams's book "Life, the Universe and Everything".
opto-camo - Optical Camoflage
Gn... xxidnt... = An... accident...
usagi = rabbit
BTW = By The Way
Vesp3r Mega Canon == Sw33t aw3som3z = Vesper Mega Cannon == Sweet awesomes
Vesper - Erika is armed with the gun from Mahoromatic
FYI = For Your Information
B33p. = Beep.