what do you have to back it up?
If you read the post I said "Fundamentally".
As in - does he have the fundamental (i.e., shooting mechanics) to consistently hit a 3pt? I'd have to say yes. A number of videos have been posted on this site demonstrating just that.
The same with Free throws, inside game, etc, etc. His high school videos demonstrate that he can fundamentally do those things.
Valanciunus for example - I don't think he has the fundamental to consistently hit a 3pt. Nor can Vesely hit FT.