Then regarding the tenant, money now is better than later if you want to sell - so I'd suggest exhausting all possible avenues with the tenant as far as getting them financed and cashing you out...then if not, are you really going to settle for land contract or instead, let the lease run out and once current tenants are properly, kindly moved out, do a light rehab and get better price? 

After the debtor has exhausted all state judicial options for delaying, stalling, scamming, etc., further delay via Federal bankruptcy is available to him4.  

I want to know if it is legal under the California ADU law to build another duplex in the back.More of an "FYI" than an answer to your question. 

You did not disclose what kind of saving you have, which is fine for privacy reasons but I would not exhaust ALL my cash reserves to pay off the cards.

But wherever you saw the quote that multifamily had lower default rates, I'd bet they were referring to larger complexes.As far as the low money down though, you are far better off trying to get that with a duplex than an apt building.

I will exhaust all other options before taking this approach. 

I don't think three days' instruction is going to give you much more than an overview of the process & a general idea of what to look for.

It's exhausting!

Anyway any over $50k even with more than an acre of land set on the market for a while I definitely wouldn't want to hold one with Hard Money.   

I have exhausted my funds and need an additional $4,000.00 or less to complete the project and pass inspection.