Right off the bat, my biggest concern are those two big Variable Powers the thing has. VPs can be... troublesome in any game, and two VPs seems a tad like overkill. Do you need both VPs?
Some examples -- say, 5-10 "forms" -- of what you'd be using the Shapeshift for would be helpful.
My second concern is that you've mostly hinted at what Diplomat will be doing here in FC (where's the Personality & Motivation section?). Is he mostly just going to replace people, act out-of-character, and then watch how others react? Is he going to try to get back to the Terminus, or is he content here (at least for the immediate future)?
The third big concern is how/why his arrival didn't set off lots of alarms and make the Freedom League or Atom Family come crashing down, since there's been two Terminus Invasions so there would be some sort of rudimentary monitoring system in place by now.
You also need to list what Comprehend 2 (Languages 2) gives you. With it, you can
* Speak "Babel," so that everyone who hears you speak hears you in their native tongue, but you won't understand them or be able to read their writing, or
* Speak any one language at a time and understand all spoken languages simultaneously, but not be able to read any, or
* Speak any one language at a time and be able to read all languages, but not understand any spoken ones.