With all due respect, there are so many things wrong here, that it is bewildering.
Kessler is an astonishing athlete for a seven footer; if he is meh, then 95% of all 7 footers in the NBA are outright atrocious. It is extremely hard to say what his ceiling is, as he has only just shown his floor. Shooting is a skill many NBA players not called Ben get better and better at; not all are Jimmy Butlers, but most get way better than they are in their rookie year. Kessler most certainly would for a trade to happen need a lottery FRP plus a roleplayer.
RAPTOR, being a box-score based stat, is an incredibly poor meter for players like Vando, who do all those small things that glues a bunch of players into a team; the hustle, the energy, the ability to improve those around him are not shown in RAPTOR or similar stats. Mk 1 eyeball test seems to suggest his value is in fact increasing, and most definitely a FRP would be needed to move him.
The league knows who Beasley is. A few good or bad matches doesn't change that. His value is not going to fluctuate anywhere based on a slump or redhot strike; he might in fact be hard to move for any decent return, most likely if he is moved it will be as a filler in addition to someone else.