Keller is average in every way. He'd be the instant potatoes of offseason moves.
Sandoval is a pitch to contact junkball lefty. Not sure how well that would go over here. Not a high ceiling and doesn't throw a lot of innings for what he does.
Zero chance Kelly is traded after this DBags WS run.
Corbin Burnes is a perennial All Star and has won a CY. He's ok I guess. Only one year of control.
I believe you mean AshcrAft, a pre-Arb Reds starter. He's a 5th starter maybe.
To me, Cease is a little overrated. He's like a mildly better version of ERod. I don't think he's going to anchor your staff as he gives up too many walks and tends to get hit hard. If you're acquiring him to not be the #1, fine.
Detmers is interesting because the Sox had lots of trouble against LHB, but most of his value is tied up solely in his age.
Alcantara just got TJS this month, so why trade for him until you know what he looks like.
Singer is a two pitch guy (sinker/slider) and he's probably a back end guy until he develops a third pitch (sounds familiar, huh).