As a Baselane user and fellow landlord, I really want to understand how this went down and what I can do to protect myself.

Furnace filters can go either way; some landlords handle it to protect the HVAC system, while others leave it to tenants with a reminder schedule.

You could film your logo at intervals to add some protection from it being easily copied.

Having legal documents in place help protect you. 

What are some standard process or contracts needed before the partnership to make sure both parties are protected?

Review your loan agreement for restrictions, and consult legal and tax professionals to ensure compliance and protect your interests.In C State, you can elect to file MMLLC as disregarded entity for tax reasons.

A well written management contract should clearly spell out what is expected of both the PMC and the owner, to PROTECT both and avoid misunderstandings.

LLC are favorite protection instruments of course and ideally per property and state specific.

Hoarding is a protected class because it is a disability. 

Furthermore, some lenders have rate lock protection from their secondary market buyer, which means the buyer has to legally honor the rate.