One of your risks is that you get the money first and then get into bad deals because you think you have a need to deploy the money you borrowed. 

It drives me crazy when I hear these stories preventive maintenance is what should be practiced and discussing all avenues of the deal and the borrowers docs in advance.   

We view everytime a borrower pays off on time as a win.

You should speak with a CPA and a tax attorney to be safe.Regarding your thoughts about 1/3 equal splits - sounds good until you check out the cost of getting a DSR rehab loan or borrowing hard money.

Can you borrow 80% for 30 yrs on the investments you named?

If you are borrowing money, you are going to be using equity of some sort.

I believe that the Federal Reserve is going to cut rates by 25-50 bps at it's September meeting (no emergency cut), but that 30-year fixed rate mortgage rates will rise to upper 6s low 7s around the same time, and Commercial borrowing rates, including for multifamily, will increase as well. 

Can have a huge impact on cash flow for borrower.  

LLC/ Corporation documentation (Must be a US based corporation or LLC) Most lenders may require a minimum credit score of 650 for this program if the borrower has US credit. 

I borrowed 1k from a friend and invested it into a stock which has grown to 1.5k.