What tips do you have for doing well in Warzones? I can place close to the 50%mark in a group but some commandos dominate and I can't figure out how they're doing it.
Rule #1: accept your role, which is support DPS. You don't really have a lot of on demand burst potential, so you should be avoiding 1vs1 scenarios at all costs. Be sure to save your stun and KB for when they do happen, or you're toast. Otherwise, assist melee by helping them burn down targets.
The off-heals of a DPS Commando are sort of a tossup. The big heal costs 4 Ammo, and it's not that great. I will throw someone a heal if I'm at or near a full bar, but that's about it. Sometimes you get lucky with a nice crit that makes it actually helpful, but usually it's just better to assist with damage.
How do you deal with defending yourself?
The single best advice any DPS Commando can give you is this: stay small. Don't fight out in the open and make an easy target of yourself. You need to be able to stay near LoS objects and keep at the 25-30m range at all times. If a melee makes it a point to come after you, make them work for it. Ideally, they should be 1/2 dead before they even reach you.
Assault all the way. Gunnery has no place in PvP in my opinion due to lack of mobility. You need to keep on the move at all times in PvP so that you can keep away from leapers and avoid focus fire.
Do you play from the outside supporting or get into the thick of things with everybody else?
Yes, see above. A Commando DPS biggest advantages are range and LoS. Use them. I finish most matches with under 5 deaths and quite a few with 1 or even 0...all while getting top damage, or at least top 3. That's doing your job as a DPS Commando: staying alive, staying out of the fray, and supporting melee. Melee classes have the defensive cooldowns and stuns to be effective in close quarters...you don't. Stay away from it.
Do you gear for more damage or for more protection?
100% damage. Commandos can't equip a shield, so it's pointless to stack defense stats.