Michael,If the builder and/or HVAC contractors gave you proof of Insurance. 

Proof of landlord liability policy (a must)!

Not water proof etc.

Some will want full tracing proof.

There are loads of other investors and free resources that you can find here as well.Real estate is not rocket science; don't be convinced that there are secret, magic bullet strategies that result in quick, short term wealth.

Depending on location (state) there are options for 80% cash out with no seasoning as long of proof of rehab is provided.

bondo glass" (also polyester resin, talc with fiberglass cloth strands) & similar is the "lowest" group of products I would even remotely consider for exterior/occasional water exposure.

Also, if the Builder had to pull permits from the town, they may have had to show proof of insurance and that may be on file. 

Another unfortunate situation with a lot of these sorts of tenants is that they are "judgment proof", meaning, even if you were to sue them for damages, they do not make sufficient income or have sufficient assets to collect on your judgment.

They would have to have a compelling reason to do so like a fully executed purchase and sale agreement and proof of funds necessary to close.