Was any of the tpe used? Sill have hopes for Cam johnson 
Actually, Spotrac is showing that a portion of the Schroder TPE was used. The trade would not work otherwise, at least not straight up.
Yes, but until a deal is finalized, it can be added to. So the following deal works:
Nets get:
Payton Pritchard
Draft compensation
Thunder get:
Justin Jackson
Draft compensation from Celtics
Something extra for facilitating because they need to interact with the Nets in some way. This could be the rights to an international player who's never coming over.
Celtics get:
Cam Johnson
Mike Muscala
They use the TPE for Johnson, and Pritchard's and Jackson's salaries for Muscala.
It's not happening, but it's technically possible in the world of legal trade construction.
(And actually the deal would be larger, because Johnson is coming over in the Durant deal, which presumably also involves Indiana and Milwaukee for the Crowder portion, so really OKC would have to get something from one of Phoenix, Brooklyn, Milwaukee, or Indiana to make it work, but it would likely be Brooklyn in this not happening deal.)