I think you've gotten a pretty good idea on the biggest issue - time management!! My son struggled his freshman year with the time issues and had actually decided to quit baseball after the spring. He was about 12 hours from telling the coaches when a friend (former player, coach, etc) took him out to lunch and basically told him "hey, everyone feels that way after their freshman year". He stayed and is happy that he did.
With regard to pitching that you'll see....answer these questions and we can give you a better idea
Do you regularly see kids throwing 85+ on your HS team? How many AB's did you have last year....how many K's?
Where did you play in the summer? Did you go to the bigger events like WWBA? How'd you do against the pitching you saw there?
What level of D3 are you going to? There is a huge difference between the top D3's (they'll have multiple 90+ guys) and lower level D3 (maybe nobody over 85 on the entire roster....some struggling to touch 80)