While i dont think marauder is perfect, I agree that if you are getting thrown off a catwalk, its your own fault. I've leveled 2 Marauders and 1 Sentinel (server switching to play with friends) and never have any problems in huttball. I get the top (or close to) kills/dmg along with some caps. Truthfully i think huttball is the best warzone of the 3. It requires situational awareness and not just RAWR I HIT YOU AND YOU DIE!. People complain about it too much, usually because they fail to take the time to look around at where they/their enemy are or whats going on around them.
Also disrupt works just fine for me and as someone else said i dont use crippling slash. With immobilize effects and my run speed i dont really find a need.