how does the one per turn rule work with things like:
The Tie Phantom; if it boosts as a decloak can it boost as a action (if it has engine upgrade, of course).
The ability of Turr Phennir, I assume Turr Phennir can't boost shoot then pilot ability boost in the same turn... I was considering sticking expert handling on him.
Boost as a decloak?
Decloaking isn't really a boost action.
As per Turr Phennir, you are correct. If his first action is a boost, he cannot use his ability after shooting.
We played a few games before we knew the rules really well where we stuck EU on something with boost and EH on something we BR just so we could do it twice in a round. I don't think it would have broke anything in the game but man was it fun.
I love Turr. You're just going to focus and after shooting know that it's BR/boost and the other if you can get out of arcs and either BR/BOost to get a range category out followed by evade if you're getting shot at.
No matter what you choose for decloaking, the move isn't really any kind of action so you are free to decloak and either boost or barrel roll in the same turn, assuming you have that capability.
Turr's ability, on the other hand, is clearly identified as an action, and you can on,y perform a given action once per turn, so yeah, you are correct.
This distinction us one of the reasons the phantom is so crazy maneuverable.
Thanks everyone! I figured that was the case. 
I might just try Echo+ Engine Upgrade+Push the Limit.
Has anyone tried this build?
I would be hesitant to put PtL on a phantom and risk the stress preventing it from cloaking.
Yeah, that's one big drawback of the Phantom to me. He can't really do red maneuvers, as he really hates stress. Makes me consider running Yorr with one some time.
I might just try Echo+ Engine Upgrade+Push the Limit.
Has anyone tried this build?
With Echo's super jinkiness, Engine upgrade is somewhat underwhelming. The standard upgrade seems to be Advanced Cloaking Device. The longer you can keep Echo cloaked, the less harm he's likely to come to. You decloak, shoot, then cloak again, denying the opponent a chance to shoot back. And given the maneuver options from decloaking, it's not too hard to get into a good firing position.
Sorry I meant expert handling, not push the Limit!
Yeah, that's one big drawback of the Phantom to me. He can't really do red maneuvers, as he really hates stress. Makes me consider running Yorr with one some time.
My local store runs achievements, and I ran Whisper, Yorr and Backstabber together as a 90-point team. Yorr and Phantoms go together like peanut butter & jelly.
I would be hesitant to put PtL on a phantom and risk the stress preventing it from cloaking.
only if you're using ACD
but then again.. why wouldn't echo have ACD on?