1) Expand the draft from 2 rounds to ... infinity?
2) Any player who has graduated HS or is 18+ is eligible to be drafted.
3) A drafted player may go straight to the NBA, or to the G League, or may opt to go to (or remain in) college
4) NCAA eligibility is retained until such time as a player actually signs a pro contract. Being drafted means a team owns you, but it doesn't mean they're paying you.
5) Any player who does not sign a pro contract has their rights owned by the drafting team for one calendar year.
6) Highly drafted players can receive signing bonuses and/or "major league" contracts and still be assigned to a G League squad for a year or three while they mature as players. Lower drafted players would get a standard or pick-scaled contract.

Yes. This would absolutely obliterate the level of talent in the college game. On the other hand, it would mean the kids who are in college actually want to be there. It would do a number on cheating at the collegiate level as well. I'm sure there ARE financial issues at the high level collegiate baseball level, but they pale in comparison to what goes on in basketball.