Whats the cap for a superstar you think?
JS: 18 - JR: 11
OD 17 - HA 18
DR: 19 - PA 17
IS: 12 - ID 9
Basically shave 1 off most of the numbers, would that be possible for a superstar?
I typically suggest looking at the TL to get an idea of what is possible and what isn't for certain potentials, but you 100% cannot reach that with 8 potential. 17 passing alone will almost cap him.
I would go much lighter on passing and stack up more OD. OD is the most valuable skill both for games as well as resale value. Passing is expensive and takes up a lot of cap space, so I wouldn't recommend going above 12.
Something like this is probably rare but possible:
Jump Shot: stupendous (17) Jump Range: prominent (10)
Outside Def.: legendary (20) Handling: colossal (19)
Driving: legendary (20) Passing: prominent (10)
Inside Shot: prolific (11) Inside Def.: prolific (11)
Rebounding: inept (4) Shot Blocking: respectable (7)