Francis7 I am not sure where your going with this, IMO playing college baseball is not anywhere near as important as getting a college degree. College baseball is hard, really hard, and when you add in the academic requirements it's really really really hard. If a student is borderline academically then he better focus on academics exclusively because he will be cut in the fall if he cannot maintain an acceptable GPA. RJM is right the forty year plan is what is important. If he wants to play college ball and is borderline academically or has a learning disability - get on the club team. 5 years after graduating a degree and job opportunities are what is important, baseball memories will fade away.
As far as categorization you can not broad brush college baseball programs, a Power 5 school is light years better than a RPI 150 school. I have also seen D3 college teams that could not beat a good HS team and I have seen a few D3 teams that could easily compete with mid range D1 conferences. I would say that the range of baseball is D3 is much wider than D1 with the top 25 teams quite good and then a big drop off after that.