Pay no attention to the naysayers, it's perfectly viable for 50 PvP. Yes, you have enough power to cause damage. 300k damage, 200k protection is not uncommon for me. Wearing a full set of Supercommando armor is pointless though, see #3 for the gear I use. PT tank damage is better than Jugg tanks, but still less than Assassin tanks.
You want to be in the thick of things, where all the action is. You have a lot of AoE at your disposal, including an AoE taunt. Run w/ a guild healer and toss guard around to protect your teammates. Be support DPS and help focus down enemies.
I use all Aim augments. I have tank implants, main hand, and offhand. The rest is DPS gear.
31/10/0. Take those 2 points out of Iron Fist in the Pyro tree and put them into Advanced Tools. The shorter cooldown on Grapple is well worth it.
You do actually have a level 50 powertech/vanguard, right? I recall that you used to say that mercenaries were fine and that we all just needed to learn to play even though you never leveled your merc past 34 (or something close to that).