@Gyroscopic Alignment: I don't see why not, if you are a merc you are an easy target for people and you will always get stunned alot in pvp. I feel this helps with heat management from my personal experience.
2/2 Energy rebounder is needed for you to be able to use Degauss when you need it (unless there is some bug I am unaware of). It is counter productive to have a snare removal up only half the time in a game with alot of snares and melee.
IMO You don't need 3/3 on Burnout in PVP simply because it's a very conditional situation in which a target is below 30% in a game with powerful healers in pvp as well as medpacs and offheals. I would rather take 2/3 and put that point into Energy Rebounder for the reason above in which this skill will constantly be activated due to frequent pvp damage taken.
Regardless, these are minor talent changes that come down to preference.
Yea they are pretty much personal preference. One thing I'll point out to you is about Energy Rebounder and Degauss. You said that you need 2/2 in energy rebounder for Degauss to be good. The reason why my build has only 1/2 in energy rebounder is because of its effect. With 1/2 there is only a 50% chance to lower CD on Energy Shield....but its a 50% chance any time you take damage. For example, if someone Rapid Shots you....it hits you multiple times so the 50% chance is almost a guarantee since there are 3 or 4 chances all at once.
Also I find that my defense vs melee has to be one the following:
It gives me a 3rd option for escape.