The talent Power Barrier should be buffed to 4% less damage taken per stack, maxing at 20%, as well as lowering the lockout duration of interrupted abilities by 10% per stack, maxing at 50%.

I've decided that this one change is all Arsenal needs to be balanced in PvP. Make this happen and Arsenal will be fine.

Oh and this:

Tracer Missile should have it's animation change reverted.