I wonder if it might be helpful if we seek a DOL opinion in the matter.

Good luck brother, I hope this helps, I genuinely think this is the best thing you can do when seeking a mentor. 

"Seller" includes an owner of property who is seeking to sell the property and a landlord who is seeking to rent or lease property to another person.

A great place to seek advice.https://www.facebook.com/groups/REIforTheW2/Look for Jay Helms on here!!

What services/companies do you recommend for credit checks?   This would be for a condo rental in the state of Alabama. Thanks for any suggestions and possible cost. 

2) Should I contact a lawyer to seek relief against the former owner?

I am seeking to find professionals to help grow my passion and interest in becoming financially independent.

There's no penalty to a buyer for being unrealistic about rehab costs.

In most states, if the tax lien is paid prior to the redemption date, you as the buyer will pay the taxes, penalties and often interest back to the individual who purchased the tax certificate, or the county if no one purchased the tax certificate.

All with 15% down based on purchase price + rehab dollars using ARV from the start AND projecting future rent to allow you to get 75% of the future rent as extra income to qualify for the loan; 30 term, rates around 6% these days, no pre-payment penalty so you can sell when ready and repeat.