If you have a recorded mortgage and the county did not properly notify you about the tax sale, then the tax deed can legally be voided.I would get a copy of the tax collectors file and see if there is any mention of your recorded mortgage.I would talk to the tax collector and see what the story is and then inform your attorney.

Provide proper notice of non-renewal near the end of the lease term and then sell when they move out.

I am looking to make my first investment, and am curious about how to do proper market research.

A proper lease with separate option to buy I don't think is a starting out proposition.When it doesn't work with your cousin do you have a back up plan? 

As long as it was done properly, we'd be fine.

As others mentioned, you will still need to find an attorney or title company to ensure that clear title is properly transferred from seller. 

First check that the tenant was properly served notice to move. 

You still need to do a proper move out inspection, but a pre-inspection means you can make sure the place is good to show and make a list of what you need to do.3.

The paint smells super bad so whoever is spraying it will need a full respirator and proper ventilation.

Talk to insurance agent about umbrella coverage and mitigate most of risk that Properly prepared LLC is meant to avoid.