I knew there were some HML lenders that did OO, but OP credit score “isn’t great” (which likely means it’s poor) and “technically don’t make much money” (which likely means he has little income).i think it is long shot any HML that does OO will take on this risk for what they can legally charge for OO loan.  

I'm 53, married with 2 kids less than 17 years old with debt only from purchases on credit cards and my home.

the note is converted or exchanged for credits?  

When you tell them they will only get paid when the loan closes, they will disappear.If required, the only money you should ever send to the lender is for a credit check.

Required good credit, adequate reserves, full doc commercial loan with a personal guarantee.  

LLC Transfer & the Due on Sale Clause•HELOC: If you take out a Home Equity Line of Credit (HELOC) on your rental, most lenders require the property to stay in your name.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

If it is a credit/equity line, you could provide a lender letter that the funds are available immediately for funding - and cured any recission period. 

These properties can provide cash flow and diversification while qualifying for favorable residential loans.

@Hank Bank BRRRR is probably want you want to do.Buy, Renovate, Rent, Refi, Repeat.Before you go all in and either find out you don't like being a landlord or you make costly mistakes, start with just the next one.You'll have some challenges with tapping the equity in the townhouse:1) What loan amount can you qualify with your credit & income?