We are also planning on doing our own subcontracting (no GC). giving the nature of our cousins business we are using many of his connections as our subs, (he owns a waterproofing company.)

There is no good events from natural disasters but you might wait a lifetime for one to hit 

Has anyone dealt with this type of a scenario with the sale of a property during or after a natural disaster.

They are going to look at how many debts you've had in the past, the nature of the debts, how long it took to pay them back, if you were ever late, chargeoffs, etc. 

I could see them wanting to insure you during a natural disaster.

https://www.nbcnews.com/storyline/hurricane-harvey/first-they-fought-storm-now-they-fight-their-landlord-n799206If you live in an area prone to natural disaster's maybe the lease should spell out a course of action.

Service charge if property is located in building with multiple owners (150-350 € p.a.)Also, depending of the nature of your contract you eventually are liable for stamp duty (10 % of one month rent, upon signature of the contract).In overall very dry deal.

It's like a get rich quick scheme and I fear that it is predatory in nature.  

The house has natural gas lines running to the gas furnace, the kitchen and the laundry room. 

They still maybe never to heard from, and that could just be the nature like I explained above, or it could be him.