ToD, that's pretty much the build I'm running atm, and at lvl 29 with 15/23, it's been pretty damn fun and effective. I'm sure the MW arbalest helps, too
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I think the biggest thing that helps with being a Crossbowman is the same thing that helps with Any class.... The buddy system. Your shortcoming will be in melee, so stick with someone who focused in melee. There was a case where Relit (A pikeman) and myself kicked the shit out of the opposing team because he'd rear horses, and I'd shoot their riders, or I'd get the attention of foot soldiers, and relit would poke them, and I'd switch to my 1h and we'd just juggle the shit out of them, or he'd Cover me while I reloaded, and we'd just have each other's back. It was extremely effective, and extremely fun.
Otherwise, just make sure your Manual blocking is up to par, reload whenever you have the chance, and just play like you're an Archer with a hella-slow rate of fire, but better melee capabilities (depending on what your archer build is).