If the deal collapses and I would lose everything, I'm out.

This house was purchased right before the collapse in 2008 as my primary residence and I converted it to a rental out of necessity.

Usually, only heating oil USTs associated with commercial properties are regulated. thus, most home heating oil tanks may and often are taken out of service without any oversight from state regulators.Second- the rules that are in effect for heating oil tanks are usually less stringent than for diesel or gasoline tanks since heating oil tends to thicker and may not migrate as far. as a result, many states just require tanks to be cleaned out. they may also require the tanks to be filled with sand or concrete to prevent collapse. but sampling may not be required.Third- the key to determining if a tank has leaked is to collect soil samples from around and beneath the tank (groundwater also if groundwater is shallow). another quick way to see if a tank is leaking is to "dip" it with a stick that has a paste that turns color in the presence of water. generally, if water has gotten into a tank, it can mean oil has leaked out of the tank (although a certain amount of condensation may be present even where there is no leak so this is not a infallible test).Fourth- if there is currently a tank in the basement, ask the owner if there used to be a buried tank (a/k/a underground storage tank).Fifth, If the tank has impacted the soil, the cleanup generally varies from $25K to $50K though the costs will depend ont he depth of the contamination. i once had a home with a heated pool that had pressurized piping and used diesel. the contamination went down 40 feet and the consultant went crazy excavating the soil to the tune of $400K!!!

Compare that to when Wall Street collapsed or currencies that aren’t backed by anything tangible"https://www.cnbc.com/2019/10/01/real-estate-is-still-the-best-investment-you-can-make-today-millionaires-say.html?

Need to budget for it to collapse.

I expect it will happen, my property will revert back to a family vacation home, and the economy there will collapse. 

Some areas in the south have suffered the worst impact and collapsed structures (houses, schools, churches), along with other infrastructure damage such as bridges, buildings, streets, etc. 

That said, LLC's are vulnerable to the corporate veil being pierced and the protective walls that were in place coming collapsing down. 

Look at your options#1  you sell an old property, get dinged with capital gains but have an opportunity to buy a newer better maintained property#2   you can refinance take out enough equity to maintenance home and get new tenants and possibly purchase another rental#3   you do nothing and hoping a 100 year old home doesn't collapse..predicting market conditions may not be wise.

Unless the seller was blatantly covering up a HUGE issue (like recently constructing a wall in front of a collapsing/leaking foundation), your chances of successfully wining a lawsuit are very low, and your chances of actual recovery even less.So what do you do?