I am mainly interested in small multi-family properties (2-15 units) with value add potential.

That means paying whatever bills you have accumulated, at least on time, and reducing your debt load. 

There are 2 main ways to "fined a mentor"1.

I had thought of seller financing - would that raise their debt to income ratio and lose approval for lender on 1st mortgage?  

If the properties are in Los Angeles, Exit all of them immediately and let someone overpay in the current LA market, Then purchase an apartment complex at the Institutional grade that will deliver you a couple of million a year in cash flow.When I worked in Private Equity and a new client showed up with over 20 million worth of debt free real estate spread out over 15 or more properties, It always surprised me that consolidation into one asset never came to mind.   

I have no credit card debt or any other debt (ie car  payments, student loans etc).

Most claimed turn keys are rentable but mainly on borrowed time with mechanicals, kitchens etc all aged and due for replacement.

So, the main option I have heard is find a partner. 

I'm mainly looking for SFRs outside of Santa Monica.

As brokers and investors, what are the main challenges you face when doing deals?