We also paid for an inspection on the house & 2 appraisal fees.I called Nick to ask questions and he didn’t like the questions I was asking so called my partner and told him I needed to back off or they’d cancel the deal!

There is no additional "risk" on the note like a demand clause etc, but you have  extra expense in upfront one time costs and the pre-payment penalty that most programs are sold with if rates do drop as expected in the future.  

And at what nominal price compared to the $24mil they paid in 2019? 

If tenant raises factual defenses such as falsifying the lease or claiming they paid rent, there would be a brief trial which you would be prepared to testify against. 

Promising a high payback percentage plus a point for each month it’s not paid.

Also, after a year, the mortgage hasn't been paid down by much, especially if it's a 30 year mortgage.The only challenge you may run into is if you purchased it using a low or no money down mortgage option like FHA or VA lending.

I found really good deals and paid cash.

In most situations, the more profitable a property is, the higher percentage the GP is paid.

I paid off the loan as the solution.

So if we go w/ the $700K purchase price of the new rental (paid in cash from the proceeds), that leaves them w/ $300K to pay capital gain on, @15%, totaling $45K.