With rates as low as they are right now, you are essentially shorting the dollar. 

My wife was on with 911 and the operator could not find the address for the cabin; so, we had to grab the rental paperwork and fortunately, the owner included the 911 address on it.  

The draw back to these loans is that they are more paperwork heavy than the other "portfolio" types of loans....but if you have ever received a loan on your primary home, it's likely that you will go through the same type of paperwork here with conventional lending.

I would guess this needs to be deducted off the income of the newly acquired properties, even though the "paperwork" states that the interest is against the initial property that the cash-out-refi was against.

I also furnished the living, dining, and kitchen for free, essentially--my son's moving in (we hope) in 2022, so I'd have to furnish it then anyway, but I'm not getting paid for it this year. 

Base your new offer on the value you have determined once inspected paperwork and property.

I personally could not see an arrangement where I put up all of the money in the project and take on essentially all of the risk (other than your opportunity cost) and accept less than 50%. 

Therefore, they’re essentially my bosses.

Take control of your personal finances right now, eliminate expenses that are not essentials (Netflix, car payments, that new $1000 iphone, that $120/month cable bill, etc) and start saving up that excess so you can invest.

Can you figure out what the reason is for not wanting to fill out the paperwork?