Now I have $550k cash left over to either buy another properrty or invest it another way.

1/3 of rehab loans are defaulting right now...If you have zero capital, I'd just get to work. 

Depending on credit history and how the property would perform from a rental income standpoint you may have access to up to 85% financing on an investment property 1-4 unit purchase. 

I am fully educated on what's public online/and how to access that easily, and I'm looking around for subscription/pay options that offer more "actual raw data" (on deeds, history, leins and public records) than the county sites, basically.Research--for anything I identify as potentially interesting.

Sounds like you are just now filing your 2022 taxes.

I take less issue with equity pay down but this certainly has a cost to access.  

Now you need to figure out how to find deals and pay for them.

It sounds more like the applicant purchases the credit report and gives access through the credit agency to the landlords who have to accept it if it is less than 30 days old.

Required repairs for federal lending approval are generally more easy to include.We've seen folks with helocs attached to the property who have accessed the heloc to repair the property right before the sale since the heloc has to be paid off as part of the sale. 

Hopefully this is not some news to you, but sellers are no longer having to pay buyer agent commissions, now is a Choice, which might be confusing, but there is nothing to worry about. still, it doesn't change the fact that to maximize profit, it's wise for sellers to offer a buyer agent commission, attracting more qualified buyers to the listing. and for buyers, the main change is the need for a few extra forms and agreements before viewing properties.