I'm in a 12 team/7 player keeper league (so 8th round is first draftable round).  There is no draft penalty on any keeper and you can keep them forever.

I have Kris Bryant who was one of my 7 keepers this year. 

I have been offered - Ryan Zimmerman, Yasmani Tomas, Taijuan Walker, and a 9th rounder

for - Bryant and a 10th rounder

I really love Bryant and think he will be a star for a very long time (as does the guy trying to acquire him), but Tomas and Walker have a lot of potential and Zimmerman is still a quality player.  Thus my struggle.  If I accept I would likely drop Chris Carter and Dalton Pompey.

Would you trade Bryant for that package or hold onto him?  He should be called up very shortly and he tore up the preseason.

No. That's a lot of eh for a guy who will be a star this year.

Not a chance. See what he does. If you get offered a package too good to not take you'll know it. This ain't it.......