Hi!
I'm actually a BU student graduating in September.
Based on my personal experience and also what I hear from others, being pre med overall is good at BU because you have A LOT of resources and opportunities available since the city is congested with hospitals, clinics, labs, etc. Also the pre med club and pre med office constantly send out emails about jobs, volunteering, shadowing, and research opportunities.
Advising, however, in my opinion is meh. I've had a few different advisors but stuck to talking to only the Dean of Pre Med office since he's seems to be the most knowledgeable and scrolling through SDN regularly.
As for classes, idc what you hear but most people at BU know that grade deflation is real for the intro classes specifically for intro chemistry and biology (aka the weed out classes) so make sure to read up on RateMyProfessor to find the best prof teaching that semester if you want to do well. The upper level classes are reasonable in comparison. Also, as I spend more time at BU, I figured out which STEM classes to take that are likely to be GPA boosters.
For BME, its actually a very common combo from what I hear since a lot of the major requirements are pre med requisites.
Hope this helps!!