You will have access to the mls but also to Imapp (great free software to search public records, and create mailing lists such as deliquent property taxes, expired listings, absentee owners, ect).

I'd disclose to your broker of record what you are doing, but there should be no commission, transaction fee, or other payment to your broker if it's not on the MLS. 

There could be involuntary liens such as code violations, water and other utilities that survive foreclosure  and are not necessarily recorded 

The property had mortgage recorded in 2009 and has a senior 90k federal tax lien from 9/7/2010--- per this clip from the IRS website, and it being over 10 years, would that mean I'm safe?!

I have a bank with which I have some loans but now they are requiring all information including all rent rolls, tax records and even P&I payments on all of my properties, including ones that I have loans with other lenders.

We all know, it is easy to go into the tax records and get the owner name and address but if they want to find me, they will need to work a bit to secure the contact info.Hope that helps. 

Take a look at the public records for other rehabbed properties in your area.

I found it by researching the county tax records for multi-family properties in the market I was interested.  

Because the actual data points to businesses closing in record numbers due to Covid, let alone increasing rents.Those new entrants should have better build those cost into their business model, or they won’t be in business for very long.

Additionally, I'd pull the permit record for the address (usually available with the city records office, often online) and see how officially they did the deep work.