Here is a scouting report. This is only his weak spots. Thoughts:
His lack of strength and experience can be taken advantage of fairly easily by older and more physically mature players. His lower body in particular is underdeveloped, as he gets backed down fairly easily inside the paint, and is very foul prone at this stage at over 7 fouls per-40 minutes. He's also a poor defensive rebounder at just 4.7 per-40, something he should be better at considering his length and athleticism.
He isn't the toughest guy you'll find right now, which plays against him with his ability to finish effectively around the basket in traffic. He's converted just 49% of his attempts around the rim this season, and doesn't show any real resemblance of a post-game to take advantage of his superior size. He doesn't get to the free throw line very often (2.2 times per-40) as he tends to avoid contact around the rim.
As skilled as he might look in warmups and in occasional flashes he shows in games, he isn't a terribly consistent shooter at this stage, making just 33% of his 3-point attempts and 58% of his free throws. He can get really hot at times, like he did at least year's Nike Junior Tournament, where he hit 13/27 (48%) from outside in five games, but he'll need to keep working on this part of his game, particularly in terms of speeding up his release and avoiding dipping the ball substantially before he winds into his shot. He'll almost certainly need to be effective with this part of his game to make up for his lack a back to the basket arsenal.
What's important to keep in mind is just how young he is. He is one of the youngest prospects in the draft. Players his size usually take longer to mature physically and really blossom, so there is a lot to be optimistic about moving forward.
His coach seems to like him quite a bit, as he gives him plenty of freedom to operate from the perimeter and make creative decisions with the ball, which is not exactly common at this level of basketball for a player his age. He has been averaging a steady 15 minutes per game all season long, sometimes even seeing the floor with the game in the balance against some of his teams toughest opponents, which is invaluable experience.
A scouting report a year later.
He still looks a long ways away from reaching his full potential here, starting with his body, which remains very frail and could make him susceptible to injuries if not developed carefully. He also lacks something in the ways of toughness and awareness, as he tends to avoid contact in the paint and regularly gets pushed around on the interior, not always offering up as much resistance as you might hope. The game moves a little too fast for him at times, and he doesn't appear to be the quickest thinker around, often looking a half-step slow in his reaction time. All of these things show up in his surprisingly pedestrian rebounding numbers (2.4 offensive and 5.8 defensive per-40).
He also isn't a great passer, dishing out just 41 assists in his last 1813 minutes of action over the the last three years, or one assist for every 44 minutes he plays. His assist percentage this season (and over the course of career) is one of the lowest of any player in this draft class, which is not ideal for a stretch-4 that teams may hope to run a significant amount of offense through on the perimeter.
While his superior size for his position is certainly attractive, at the moment he has very few ways of utilizing his height to his advantage besides his shooting stroke, as he has no back to the basket game and very little interest in playing inside the paint.
With that said, it's important to remember that he is still young and only scratching the surface of how good he can become. His unique combination of size, skills and mobility at 7-1 gives him incredible potential to grow into in time, even if more-so than any other prospect in the draft possibly, he needs to land in the right situation in the draft.
At 7-1, with a frail frame, and the shooting stroke of a guard, he doesn't have a crystal clear role in the NBA right now, at least not in a traditional sense, and certainly not in the short term. If his first coach in the NBA doesn't appreciate his skill-set, and isn't ready to be patient and work through his limitations, he could struggle badly to get minutes early on. Getting with the right coach, roster and organization who can develop him will play a huge role in the success he has in the NBA.