Thanks for the tips! I'd really like to try to prove that merc has the ability to be effective in PvP. Also is the Arsenal merc build the most standard for PvP or has anyone else tried any other dps builds?
Pyro is standard for PVP. The prevailing belief with Arsenal is that while it can put out *massive* damage, that's largely only if you get left alone. An Arsenal Merc in PVP is not a 1v1 DPS, his job is to burn down targets that other people are already engaging, more or less. You get a melee on you and you'll get shut down real fast.
*If* you're going Arsenal, though, do remember that Power Shot is your backup attack to proc Unload if your Tracer Missile gets interrupted and locked out.