I did my first mission the with love gun and I had the kill 5 people with an assault rifle quest but when I killed someone with the love gun it did not count as a kill for the quest.
Might be a bug?
Quit? nah just like Maplestory this is my yearly game where I will be playing it constantly for 1 or 2 months and then quit again. The game is just to unique to quit gta 5 online sucks hard so this is my only option it is still loads of funs.