“Medical Scholars” at UCR says its for transfer students like you as well as freshman.
http://msp.ucr.edu
“Faststart” at UC Riverside is the one where you need to be there for six quarters, but Medical Scholars, you may qualify for, it seems.
About 70% of Riverside undergrads commute from home. Does that bother you at all, it may mean less campus life, but I don’t know the atmosphere at Riverside.
Thats a good idea to try a short residential program at UC San Diego, . Will you hear from Vanderbilt and Cornell by the time you will stay at San Diego? The timing seems tricky for a transfer student, but good luck.