I'll split this post into two parts based on your question...NUMBER 1: OBTAINING POSITIVE CASH FLOWIt comes down to many factors, but a few key factors that I have found that have the largest impact on the property's cash flow are below (The below generally holds true for any market.

This is true in San Diego and virtually every other large city in the US.  

HOWEVER, you've got to be very vigilant on running the LLC as a true company - separate banking accounts, credit cards, books, corporate records.

If you enter a true partnership with this GC, you will be splitting not only potential profits but also potential losses.

It is true that traditionally commercial loans are going to have 10-15 year terms (most commonly 10 years) with a balloon payment.

I am trying to get a 5% down first home buyer conventional on a fourplex for my daughter to househack and lender I spoke with says that we need to calculate the debt for all the other properties I own and pay from businesses into DTI.Is it true?

It's definitely ramping up, and I do recommend caution and personal research as well, but that is true for any out of town investment.

I only invest in regional drive to markets that are tried and tested true vacation markets.

You need to understand that it is true that the housing authority pays more in some zip codes.

For illustration purposes, the majority of investors who post on BP will move the property that pencils as a true BRRRR to the front of the line over the better situated asset with better fundamentals merely because they receive 100% of their invested capital back as opposed to 90% (again numbers are merely to illustrate a point).