As you may have realized, there is a consensus among top mara players that this class is just fine. These people are usually old players and they don't care whether the ordinary folk can play it or not. They usually have a good team and know the class as good as the devs and they probably are really good gamers too but make no mistake, they'll only tell you to "L2P" but wont share their "secret formula". Marauder is the only class right now that 9/10 players cant play it in pvp but I have a feeling those 10% actually get some kinda satisfaction from it, otherwise some form of helping hand would have been in order. Hell, I've even seen players who say UR is just fine in a way as if they think It could even be further-nerfed for all they care.
Go play another class, and I mean any class will do. Yes some classes are harder to play but with the right spec, I guarantee that none will give you the pain of playing a marauder.
PS: dps-wise the class is really fine, it's the current mechanic of the game and the lack of good pvp-skills (not team utility skills like blood-thirst etc.. and besides force camo in carnage) that **** it as a pvp class.