So I went and rewatched this utter piece of crap of an episode just to see the scene in question. While I'm absolutely no apologist for TATV, I will say that my interpretation of the wink scene is different from yours. Trip is in sickbay with Archer, Phlox and two other ofiicers. If Trip really was faking it all, there'd be no reason to keep that info from Phlox (who would know if he was faking anyway) or any other Starfleet officers in the room. Unless the wink was improvised by Trineer and Bakula just went along with it, Trip's winking just seemed to be an indication that he'd think he'd pull through, with Archer supporting that feeling by winking back. Of course, the very next scene shows that this didn't happen.
Now, of course, I could take this opportunity to say how utterly ridiculous it was that no one else, not even T'Pol and Archer, had a reaction to Trip's death in any way, even though it literally just happened right before the signing scene. Everyone's all smiling and happy, and acting completely oblivious that one of their closest crewmates who'd they'd been serving with for ten years just died in the dumbest way ever.
But I won't go there.