Should we bother trying to wrestle with Trendmaker or HVAC company, who has since rebranded, for compensation (all of this did lead to significant health issues which is another story entirely as well) Question #2...

Contamination is where it can get a bit pricey, when the contamination remediation is said to be complete make sure that the property gets a clean bill of health from the state.

The neighbor who is living there has developed a pretty bad mental health issue and has become very erratic and displaying violent behavior even threatening to kill me and my tenant.

That is where I draw my take on Sell/Rent my biggest fear is the "What if Factor" - drop in tourism, association comes under litigation, hurricane (This season looks like it will be "Very" busy), Sickness or health issues or other.

As Joel notes, it is a great way to monitor tenant health and be prepared for failing tenants ahead of them stopping to pay.

This negative position can consume years of cash flow to recover.

That will get consumed with yearly expenses, especially a 3 acre lawn to maintain.  

Check out the following links where you can look them up - NYC's Department of Buildings ; Nassau County Consumer Affairs ; Suffolk County Consumer Affairs.

The research will investigate potential soil contamination, ground and surface water quality, along with the presence of hazardous substances on the site, and will include researching files from various municipal and state departments including the planning and zoning department, health department, fire department, and the Department of Environmental and Energy Protection (DEEP).

You answered your question in the last sentence - disclosures are required on conventional but not for DSCR - these are really aimed at overprotecting the consumer (non sophisticated or non real estate professional) - since DSCR Loans are 100% business purpose and for investors (and typically for experienced investors or non-first time buyers only), there is less need to overly disclose / overly explain everything in a disclosure since its assumed they are experienced and know the basics