@Zack KorensteinMy tax firm shares some clients with @Scott Smith and his legal firm.

I think it would be a nice touch for my STR, but I'm not sure about the legalities.

You can face legal issues because of the existing mortgage/loan.The other options are Contract for deed and Wraparound mortgage.

We just started with our STR (has legal TOT certificate) in Mariposa County near Yosemite.

Do buyers have the legal authority to give the tenants 30 days notice to move out immediately upon the deal closing if they don't want to continue having them as tenants?

You even indemnify GPs against false claims and sign to cover legal cost.

Given that I need to live in the home legally, I am planning to move into the smaller unit that is currently brining in the under-market rents.

Who is buying/selling (legal) stuff with it? 

If you did not deliver the proper Notice to the tenant, missed deadlines or tried something else that is not legal, your eviction case will be thrown out.A normal eviction for non-payment of rent should be settled in a month, I can only imagine that your property management company does not know how to follow the law - and I hate to say it, I know several, that do not even meet the necessary license requirements and therefore no surprise they don't know.

However, if they continue to refuse and there's no resolution, you may eventually have to look into the legal steps for eviction.