Your team is key to your flipping success. 

Buyers and sellers should consider some amount of closing money be held in escrow after closing to cover potential problems with the non-responding tenants.Does anybody have any experiences to share with successful use of a Tenant Estoppel Letter, or times they wish they'd know about this tool before entering a Purchase and Sale Agreement?

Plenty of successful investors started right where you are.

Howdy Alex,Welcome to Conroe and best of luck on your new journey.Wishing you success ahead!

Roberto, was the transaction successful? 

Real Estate is a land of opportunity but not everyone will find it or make a success of it.

Has anyone been successful with rentals without windows?

No one will care more about your success then you.

I’ve seen many buyers successfully execute this strategy over the years, turning such properties into valuable investments.

if they were that great you'd never see them because they'd all get bought up before they even came to you.I think what @Travis Biziorek is saying is correct - you need a strong network to be successful.