Just some quick points
Did Weber have talent? You.tube the Texas 2010 game, had McCamey (PG), Paul (SG), Davis (PF), Richmond (SF), Meyers (C) at various times of the game. Pretty solid line-up. In hindsight missing on Evan Turner really hurt. Rose was never coming (grades) and Gordon would of given us one year at most. Turner gave OSU 3 very good years. Also Weber recruited too many projects that could do one thing but were lacking in many other areas especially driblling/shooting.
Tilmon really needs 2-3 years, if he leaves after one year I fear he will drop in the draft similiar to Stone, Davis, Ebbisserre, and the Kansas players. Tilmon's early presence will be defense and rebounding, he isn't a ball hog. Team Chemistry is going to be very important as we will be gaining a very talented 2017 class to go along with a talented experienced group (JCL, Black, Finke, DJ, etc)
Way, way too early to say that. He might need 1, he might need 2, or he might need 3. Two years is my guess. But the thing is he's going to get a lot of playing time right away, which should allow him to put up good pts and rebounds numbers. If he looks like a top 20 pick, he'll likely go.
I would say it is also too early to say whether he will ever be drafted, or play in the NBA. Who knows what the future holds for a rising Sr. in HS. His size is much easier to see how it translate from HS to the NBA then all the talented wing/tweener players, but still.