Different banks have different requirements. 

If you decide to do this make sure to plan ahead and track the income and expenses separately for each unit since LTR tax treatment is different than STR. 

There are lots more rules and the process is very technical and unyielding.Consider AB-175 which clarified SB-1079 and significantly tightened it.Call the trustee that represents the lender and ask them what they require.

I feel like I only need to incorporate DSCRs, NPV, IRR and of course growth rates (both expense and rent). 

I am looking at a mixed use building in the 6 to 12 unit range in an expensive area of the country.

There should be an alert or something informing each party something is required before moving on to the next step.  

Whether a condo is warrantable or down payment requirements and terms structuring? 

First what's you net cash-flow after HOA fee and other expenses.

I had trouble finding a bank that would do two dwellings and ended up with a loan requiring 25% down and a few upfront points with 7.5-8% interest rate depending on lock in day.

No requirement to take Section 8 tenants.