Even stars have nights during which their shots aren't falling. There's a reason, however, why stars can shoot 4-12 while still netting 15-20 points.
The only thing missing from Sullinger's game right now is the recognition of the importance of free throws. The most consistent scoring weapons always seek out contact and try to get to the line, especially on nights where their field goals aren't going down. If Sullinger can begin to do that, I believe he's an All-Star.
This is not like saying "All Olynyk needs to do is add five inches to his vertical and he'll be able to block a lot more shots and be an All-Star." Sullinger has the size, body control, ball-handling ability, court vision and BBIQ/instinct needed to find contact and draw fouls. If he can recognize a cold shooting night early on in the game and try to get to the line 5-10 times, this kid will be a special force on the low block as well as facilitating the offense at the top of the key.