FAMAS isn't that great; I figured out how the 35-25 damage has a disadvantage to other AR's; it's ALWAYS a 3 shot kill or more, regardless. Even if you headshot, it will not kill faster. Thus, more skilled players with a different assault rifle will win if they get headshots and SMGs will beat it in CQC with Rapid Fire (which should almost always be used on subs now, it seem). It's still a great weapon, but isn't OP/the coming of God for ARs like you're making it out to be.
In Domination, K/D does/doesn't matter at the same time. You don't want to die a lot and earn the enemy killstreaks, but you don't want to have dumbass teammates sit in the back of the map padding their stats instead of capping flags. However, I hate teammates that are just the opposite, and try to capture all flags, because that's a VERY, VERY bad idea. That kind of shit lost me countless matches on Bog on CoD4. You only want TWO flags in Domination. You take TWO and hold them, then spawn kill the enemy team on the 3rd flag, and defend yours. The only time you want all the flags, is if you're so far behind, that you are forced to in order to catch up, because taking all the flags means that enemies will spawn everywhere in random spots, which will get you kiled a lot, which results in lost killstreaks, which means that holding flags will be difficult. Even worse, if you start on the good side of map, and switch, you lose the advantage.