Black Ops Tips and Classes?

Im on the ps3 play with default alt buttons everything else default (except i play with sensitivity 3-4)
current killstreak setup:
rc-xd
motars
attack helecoptor

current main class
ak74u red dot sight
makarov dual weild

perks
scavenger (or hardline if on smaller maps)
slight of hand
second chance (marathon for smaller maps)

semtex
nova gas
claymore

if im not the lvl for the gun in your class i will get to that level to get the gun (started 2 days ago currently lvl 25)
any suggestions of your owns or edits to mines would be helpful i will try all suggestions
if anyone is wondering my k/d ratio is 0.74 i want to get it over 1