The decision to deal Trocheck had a lot to do with finances, yes, but I don't think it was purely based on that. This is not the first time Tallon has dealt away a player who was perceived as not meeting expectations. Also, even after the deal they have less than $3 million in cap room. Dadonov and Hoffman are both UFA after this season, and at present they and Haula take up more than $10 million. What I'm reading is that they needed the cap room to re-up at least one of those guys, if not both (or all three). Also, they have Henrik Borgstrom in the AHL. His AHL numbers look rather ordinary but maybe they're banking on him being a star. I know there's been a ton of hype about him after he was drafted.
That said, I think Viola and his Army buddies are all flaky as hell and not a ton better than previous FLA bosses (and that's why I think that franchise is doomed and will relocate eventually) so I would not rule out them ruining everything and just arbitrarily ordering that payroll be slashed again, but I think Barkov is the very last player they deal away.