I'm hoping to have my Mom relocate there as well since SF seems to have a great community for retirees.

So, the about your mom can borrow is limited by this requirement.

Mom's IRA could not buy out brothers half since her son and her are disqualified parties to each others retirement accounts, so a sale to a 3rd party is best in this situation.  

Maybe they raise some equity direct from immediate family (IE - mom/dad/sister/brother/grandparents/uncles/aunts/cousins), but the majority of the skin in the game is the GP's own.

It sounds more likely that you managed by luck rather than by design over that time, and that's not at all usual for "mom and pop" operations, but they also often end up spending more and making less than they would with a property manager because of poor management.

The house we are considering is a new build 3bd/2.5ba in Lochbuie/Brighton Colorado which is a growing area with decent rent growth 4.8% MoM currently we think we could get $3,600/mo. if we finish the basement ourselves idk $30K?

This is a super common issue in MFH- you are't a referree or their mom.

There is NO getting around the fact that you own the property/business other then a TRUE no-recourse loan (which will not be an option for small mom and pop investors) and no if the loan is on your credit report has no effect either as credit report is NOT the only source.The premise of DSCR loans is for borrowers who cannot qualify for full doc loans for one reason or another, but it seems the real premise of DSCR loans is because of the commercial purpose designation is that a lot of states do not require licensing of any type to sell these products.

This is a mom an pop flex tenant. 

We bought a condo from a lady who’s mom passed away and she let the property go into foreclosure due to HOA dues as well as the mortgage.