Is that common practice?  

With the recent election, one council member is somewhat opposed to STR (or more strict regulation) whereas a few of the others (as well as the new Mayor) seem to support STR and trying to find a path forward to support STRs and affordable housing.

Bitcoin has not survived a real recession and government regulation is only just beginning.

While I'm learning a lot of about the investment side, please use me as a resource on Fair Housing best practices and risk mitigation (disclaimer: not an attorney!).

This may be true, but the inventory released is pent up due to expiries from covid forbearance, most likely all of these loans will be heavily scrutinized by the numerous regulators, and will be difficult to navigate. 

But would it be bad practice to already get to know sellers beforehand?

What're some best practices when looking for a sponsoring broker or at least one that will "supervise" me at the start?

@Michael Kagan, I always tell people who ask that buying San Francisco apartments is a game of regulations, sweat equity, and you need to have a thick skin and patience.

As far as underwriting deals, you just need to practice and maybe run your numbers by someone that has some experience, especially for your firs deal. 

A letter from an attorney quoting the appropriate law and CFPB regulations may be necessary, with additional follow ups.