Out of the three, I would stay away from Liberty. LECOM is probably cheaper than Nova.
I forget what the specific requirements are for Nova's MBS program, something like a B or better in all coursework, and if you get an A you don't have to repeat the course. That might not be the precise requirement but it is something like that. I'm not sure if there is a certain score requirement for the MCAT. It's definitely manageable and I believe a good proportion of the MS students move onto the M1 year after completing the program. Sorry I don't have specific numbers for you. Perhaps there is a previous/current MBS student on here.