He should be a fantastic PP player. Has he been a fantastic PP player in his career? Not really. Pretty large sample size too.
Patrick Kane
'08-'09: 80 games played, 35 PP points (70 points), Chicago with 19.3% (12th)
'09-'10: 82 games played, 29 PP points (88 points), Chicago with 17.7% (17th)
'10-'11: 73 games played, 24 PP points (73 points), Chicago with 23.1% (4th)
'11-'12: 82 games played, 12 PP points (66 points), Chicago with 15.2% (26th) [Injury recovery/center experiment season]
'12-'13: 47 games played, 17 PP points (55 points), Chicago with 16.6% (19th) [Lockout season]
'13-'14: 69 games played, 25 PP points (69 points), Chicago with 19.5% (10th) [Injury]
Seems like he does very well on the powerplay despite things.