I am of the thought process to just break the contract, as I doubt they will come after him over a 200k house.

Firstly I highly doubt renters insurance would cover this anyways and I know for a fact in my market if I required all my renters to get insurance I’d never attract nor keep a tenant .

I have no doubt I will be able to get a good tenant in quickly in my market.   

I doubt it would subordinate unless it was getting paid.

I would be in so over my head and at the end of it, I doubt it would draw any quality tenants, if any.

Unfortunately unless you're willing to file a complaint or suit and it comes out in the discovery phase i doubt you'll ever know for sure.as far as your next steps i think you should approach the broker and let them know you'd still like your offer submitted but approach it with honey not vinegar even though you may feel understandably slighted. just try some smooth talk and charm.

Hope that addresses some of your doubts and calms you down.

I doubt that it will matter as far as sound transmission from floor to floor.Maybe try it one a couple of units before putting it in all the units.

I doubt it will ever make money for you.

-I highly doubt he is licensed as a contractor(Texas does not require), however if he is an electrician I would pursue a complaint there if he did any electrical work as part of his management and failed to account for the money(Longshot but should put more pressure to make payment)The reality is that getting a judgement in Texas still means you have a very little chance of collecting.