Currently, Operatives are de facto the best healers in PVP. Our energy management is a total joke, our healing not relying on casts makes us much more mobile than sorcs and mercs and therefore largely preferred over the other two healers for both regs and rateds. I believe this spec is overpowered at the moment. I think the following changes would bring us down to the level of the other two healing ACs while not dropping us to the point of being no longer viable.
The rate limit on Medical Engineering should not be reduced below 9s.
The talent Evasive Imperative needs removed entirely. Free total cleanse/breaks most roots/shuts down several dps specs entirely, on a very short cd, makes no sense to be in the healing tree.
Surgical probe should have a small energy cost in addition to the TA requirement.
Durable Meds should be 2/4/6% or boost kolto injection by the current 3/6/9% instead and provide no energy reduction on kolto probes.
Your suggestions nerf PvE healing more than they nerf PVP healing. Healing in PVE is as close as it has ever been and these changes would be a huge nerf. The only thing I think should be changed would be the refund of tactical advantage on targets under 30%. This allows operatives to spam this with kolto probes and run around til they are at a safer health level. The stacks will run out very fast even with Kolto Probes Medical Engineering if they are not refunded automatically and healing from HoTs by themselves are not enough to keep them up.
I'm fine with your suggestion on Evasive Imperative especially since this is more of a PVP ability that does not have much impact if any on PVE.
If you are going to make suggestions do not be shortsighted. Just because you may only PVP doesn't mean that changes should be made for PVP that will hurt PVE and visa versa. There are plenty of PVP only changes. The 2 that I suggest above (one is yours I agree with) would have little to no effect on pve healing but would bring operatives down in PvP terms.