I do not personally know David. However... I am from Clinton, know a lot of people who do personally know him, and have watched him play a lot of HS football. For the record:
David was NOT a "head case" in HS. Never heard of any issues like that. He was a good kid by all accounts.
David had very good grades in HS. Honor roll kid. I do not know how he performed on the ACT/SAT.
One knock on David at the time of recruitment was that he occasionally "took plays off". This is true. I've seen it. However, he played RB, WR, DB, and special teams - so that should be considered. He played hard 99% of the time.
He was BY FAR the most explosive player in the MAC his senior year, and put up ridiculous stats despite the fact that the River Kings were really good that year, most games were total blowouts, and the starters were often sitting by mid 3rd quarter to early 4th.
He sure would have looked good in Black & Gold, but Purple & Gold suited him just fine.