I saw bits of his TV series, he's not the actor to pull-off the charade you described.Maybe Donny's team has clued Justin in on the final deal? Maybe it's just Justin that's creating all of this anxiety for some by behaving as if he's "fighting hard" to keep the status quo? Wouldn't be the first negotiation I've seen where that's exactly how it had to play out.
As to your other question, it seems Trump always has time for jokes. Surely you can't see that as a fault?
And trade is not a "closed system" exactly. Productivity changes the volume of trade in addition to the rules of exchange. It is VERY possible to design a deal that increases the exports of BOTH countries while at the same time reducing the current trade imbalance in favour of Canada.
Easy for you to say, if we sell less to the USA, and buy more from them, we'll somehow sell more to them in a productivity-pie in the sky future; but if that was a real selling point, no one has mentioned it yet; most especially not Donny. Let me know when he does.
On your other point, If they were funny, they'd be jokes. He likely thought his locker room talk was amusing too. I see it as a fault that he has time for every trivial thing, but not for just doing his job. But then, it's the first real job he's ever had.