There's 3 floors of old apartments upstairs we have an architect working on a plan right now.

I plan on updating the whole property and moving into one of the units. 

The only guarantee after buying a property is that you are about to spend a pile of money (whether you furnish it or not).

You can still find cashflowing properties in the STR areas people have been investing in, butit is just hard to find "great cashflowing" properties producing +25% cash on cash returns when planning accordingly for capex.

You could do cash for keys, to just end the lease mutually, or even see if they were interested in doing a payment plan for the rest of their lease. 

Include not only the mortgage payment but also taxes, insurance, property management fees (if applicable), maintenance costs, vacancy allowance, and any planned capital improvements.

We had changed everything in our plan, I mean everything, and we had to press for an absolutely insane price, knowing we would have to accept whatever comes closest.

You need to check with your planning/zoning department. 

California Fair Plan, ran by the state, has crappy fire only insurance and you will need a wrap around general and liability insurance with them. 

If you don’t plan on working as a traditional agent helping people buy/sell properties it may be best to save your time/money and just dive deep into wholesaling.