Between BBiomedSc, BSci, and BAdvSci, I would chose BSci. I chose BBiomedSci initially, but swapped over to BSci after Semester 1 for the extra flexibility. In the BSci you can major in any combination whatever you want given you can satisfy the course requirements, and do an extended biomed major which is the same as BBiomedSci, making the degree a bit redundant.
From what I've seen. Advanced Science take harder capstones which are more researched focused then the rest of the cohort, for e.g. the rest of Science does SCIE1000 - Theory of Science, whilst Advanced does SCIE1100/SCIE1200 - Advanced Theory of Science and Introduction to Scientific Research. But in terms of actual courses, I'm pretty sure we all do the same - making the 'advanced' tag a bit gimmicky. There are some cases where two courses will run parallel which the advanced students are the only one that can enroll in the 'higher one' but most of the time its not the case (especially given how cash strapped the university is going to be in the near future, so they will probably start removing courses/amalgamate the old ones)
Another thing I've heard is that the Advanced Science program is really restrictive. You have to pick a single major, get fewer electives, get asked to leave if your GPA falls too low (5.5 or 6 iirc), etc. Not worth it imo.
Pharmacy is pretty alright. If you have an interest in Chemistry then you will enjoy it, it has good employment outcomes, and UQ has pretty good rep for their Pharmacy School. I chose not to do it because its 4 years, and it wasn't something that particularly thrilled me. I can't really comment on whether Pharmacy would be particularly helpful in the MD, but in the talks we've been given by the Med department they've said BIOC2000 a biochem course, will be more than enough of a headstart before the MD.
Also you dont need to have the MD First Degree in the QTAC preferences. A few days after you accept your offer you log into UQ's website and swap your degree from there.
EDIT: This is assuming your talking about provisional. If not, you would have to add these programs to your QTAC, and I would definitely concentrate on employment outcomes a bit more due to the competitiveness of MD entry