If you aren't going to be living in CR full time as you try to execute the deal I do not think it is physically possible for you to obtain a loan from Scotia Bank and not worth your time to try because the rates are so high. 

FHA loans follow very strict guidelines when it comes to property condition.

Most agency loans will expressly forbid such an arrangement, so if they found out, the odds of having the loan called would be very high. 

Any good resources for learning about hard money loans?

Rates tend to be 25 to 50 basis points above commercial (5+ unit) apartment building loans, and 50-100 basis points above residential (1-4 unit) loans.

Financing options do exist: hard money loans, renovation loans, and some traditional mortgages can be used on distressed properties if criteria are met.

Assuming since you did any FHA loan, this was a househack?

The Norris Group has a hard money ADU loan, but it's short term (3 years). 

Since it was over 12 months with my HML, I ended up taking the property under my name with a 30-year conventional loan.

In San Diego at the current rates for a purchase loan (which has better rates than an ADU additions) at high LTV, I show 1% does not cash flow on a sustained basis.