He would be a great C in my eyes. A PF needs some OD imo and this player will have a long way to go to get a descent level of OD. Focus on his primary skills this season and next season try spendin a while to train JS, PA and 1on1. Getting them up towards Proficient and then get JR up at least 1-2 pops and return to train his primary skills. Spend 2 game weeks to train Stamina up some.
Good luck!
I was thinking about leaving JS as it is (7, hopefully he'll receive some JS training while training IS to 14), JR 1>2, DRI 4>6, PAS 5>8, primaries as high as possible for his potential (IS 14, ID 12, REB 12, BLO 8). And I train stamina 2 times a season (as you said). This is around 30 pops and extra JS, DRI and PAS would require more time then I'm willing to allocate :)
UPDATE - trainer level 5
Thanks for the tips ;)