Hard to believe this is a 16 page thread.
It is a 16 page thread because he is the most talented basketball player on the team.
Mmm...are you talking talent or skill?
Because talent essentially refers to the the special gifts you were born with that cannot really be taught, while skill is the abilities you can (and/or do) learn along the way.
For example, Rajon Rondo is incredibly talented because of his natural athleticism, his crazy wingspan, abnormally huge hands, other-wordly court vision and basketball IQ. These are things that can't really be taught, and they have a lot to do with why Rondo could be a multi-time all-star despite the fact that he often seemed to play on cruise control. His pure talent level gave him so much of an advantage that he could play at 80% effort and still have have dominate his opponents at times.
Sully doesn't have much in the way of physical talent, so I'd say most of his talents are more cerebral - things like his court vision, general court awareness and his eye for the ball as a rebounder. If anything I feel has average or slightly below average talent overall, but largely makes up for that with a very high level of skill.
I feel like if you want to become a really good player in the NBA it comes down to a combination of:
1) Talent (natural / born gifts)
2) Skill (shooting, ball handling, passing, low post scoring, etc)
3) Personality (work ethic, drive, motor, etc)
If you have any two of those three, then you'll probably be a very good player. If you have only one of those three, then you'll probably be a rotation player at best. If you don't really have either of those three, then you'll likely struggle to make a roster.
I feel like up until now Sully has had one of those things (Skill) on his side, and cannot get the other (Talent) - so the only way he can really achieve greatness it is by working / playing harder than everybody else. Or he could just keep the average work ethic, and remain a solid rotation player.