With house pricing and overhead being so high, the only solution is to provide supplemented housing. 

I would use it as a supplemental tool when your other sources aren't bringing you the amount of leads you need to hit your goals.

It's the California Fair Plan and supplemental insurance, and it covers absolutely nothing.

So it would just be supplemental income.

That rent by the room can supplement whatever other job she might have (related or unrelated to REI)While most of these would be self employed type ventures there should be some businesses around that already do these services that could get that stable income, or could be something negotiated with an REI/landlord to make it a salaried position? 

.- Are there any other endorsements / options that can be added to a standard policy which act as a substitution or supplemental for an EQ policy?

They will likely request a copy of your most recent form 4562 and schedule E depreciation supplement and handle your individual depreciation schedule in the K-1 for the OP units.

SSI (Supplemental Security Income) is a need based program for people who never worked enough to earn a retirement benefit. 

I'm looking to create a slight shift in my lifestyle, where I can ease up a bit on practicing and supplement my income with more passive revenue streams.

You can bring in cash from any source to supplement.