here's my experience and opinion. when u really love someone.. u tend to be less willing to bicker about little things and just let them go. this usually ends up in a relationship w/ less arguments and a lot more joy.

my senior year g/f was awesome.. not together anymore for certain reasons but it was the best.
my sophomore year g/f lasted about 9 months and we argued at least once i week after being together 3 months... sometimes i dont' even know why... a part of it also is that we spend a lot of time together so i guess argument get's easier that way. My HS g/fs.. i dont' remember arguing much at all.. but I didn't see them as much as I do the girls in college.
The last couple of girls I've been dating, if I do not have a strong feeling for them... I get irritable pretty easily and am less tolerant about mistakes and issues. anyhow, i learn more after each experience. so from where i am now.. i feel like just allowing yourself to be tolerant towards your mate is always a good thing.. of course.. having it work both ways is important as well. and from what i've read of your situation, sounds like the guy isn't very smart yet about things even if the intentions may be there. he might need time on his own to grow up because you being there is making it easier for him to justify being the way he is..
goodluck..