Muscle smarts.  

Sure, he could be hiding something, but he hasn't hid that he declared bankruptcy and had to rebuild his wealth from scratch.

Worst case scenario, you liquidate these assets, declare ACME LLC bankrupt, and everyone goes on their merry way. 

Ensure you are familiar with the Declaration and Bylaws of the specific Condo Association; I own a unit and the docs clearly state the Owner of the unit is accountable for all payments, penalties and fines, so I would never relegate paying the HOA to my Tenant.

DD then is to exclude each time as a possible risk, or determine the impact of failing the investigation.eg:  numbers show cash flow;  go/no-gounit properly zoned for my intent;  go/no-gocan't get title insurance or clear title; - - puntall encumbrances (2nd, 3rd, liens) understood and declared; go/no-gocan I market/rent at FMV and make a profit; go/no-go roofing; $$$foundation; $$$plumbing, including sewer line inspection; $$$heating & cooling equip; $$needs paint, just a one time expense $broken window, awe heck, smallish, one time expense $go thru the list and PUNT if the pain gets too much(expensive) OR make an offer if you can live with it.

I did get one potential lead from someone that may be declaring Bankruptcy.Good luck with your responses.

Later , he moved to CA and declared(check public records to finish this sentence) and then started doing it again.

I previously had a more normal type of slab leak on a different unit with more normal costs to fix (I think it was ~$3k total cost including water loss) and had not declared it against the insurance (but now wonder if I should have). 

Who is declaring this requirement?

These days, I've found they must declare at first meeting whose interest they actually represent, and the agents I work with will sign that they represent me for the specific properties they've shown me only, no exclusive buyer agent agreements necessary.