Hi there! I am about to graduate from the MBS program, so I can answer that for you. I worked between 16-20 hours per week and was able to maintain good grades in the program. The majority of students chose to not work during the program and I don't blame them. It ultimately comes down to your time management skills and your background on the topics. I know of a couple of students who worked 30-36 hours per week and were still pulling it off. It is a heavy course load, 8 courses per semester, but it is more than doable. I hope that helps.
Also, in regard to your second question. The first MBS class had a few students who were waitlisted from the MD program and were offered conditional acceptance to the MD program as long as they completed the MBS program with a decent GPA (3.5 or 3.7, can't remember which). For the Class of 2020, no such conditional acceptances existed. The other students, which did not have a conditional acceptance, had to apply and were then selected from.
For those asking for a FaceBook page, the link should be coming to you guys shortly directly from the program director.
There were multiple students accepted after May 31st last year. Do not lose hope. I know of a couple of students who were accepted days before the program began. Best of luck to you!
For any other questions, feel free to reach out.