Can only speak from my son's experience. Just one kid in one program. But I think the degree of detailed hands on coaching you get depends on a lot of things -- where they see you fitting into the program being chief among them. If they see you as a stud, who just needs some fine-tuning, it's one thing. They will invest the time to help you fine-tune. But if they see you as a role player seems like it's more of a "step up or step aside" kind of approach -- at least that's the vibe in my son's program. Not much coaching energy is invested in the lesser guys. Not to say that guys didn't get feedback. But it was mostly on them to find a way of incorporating that feedback.
I'm sorry that I'm so "late to the party", but I've been busy the last few days moving our son (former DI pitcher who transferred) to another state. (Back is sore from lifting and from driving UHaul. ;-)
You've already received some of the basic transfer information from others in this thread. Your son will need permission from his current coaching staff to contact other four-year colleges about a transfer. If he goes to another D1 program, he'll be required to sit out from competition next year (assuming he was on scholarship or was recruited to his current program). He could take that as a redshirt year, and still have three years of eligibility remaining, as long as he doesn't transfer within the same conference. That will depend upon the rules of his particular conference.
He can transfer down to a lower level to be immediately eligible next year, but if he then desires to return to the D1 level, there will be additional requirements and/or restrictions imposed on him. If you want to discuss his situation privately, you're welcome to contact me at 913-766-1235 or at rick@informedathlete.com.