Their money is loaned so they should be earning interest.

If you're taking a DSCR loan you could choose an option with a lower prepayment period if you want the flexibility to refi sooner and don't mind a slightly higher rate in the meantime.

Have you heard of DSCR loans?

Usually the minimum loan amounts are higher compared to a 1-4 program with a loan minimum often of $400K.

I bought a property through Miami Life Realty to ABC Capital Management with a loan from a company that I am not sure if it even exists, since there are many different companies with same name, but the address does not match anywhere and on the papers i've signed there is not any representative from the lender's company.

Refi to get a better rate is good but have to weigh the cost of money and the time you have the loan to see if it is worth the costs to get a new loan.

As a private lender would you pay the full 100%, or still do 75% Loan to Purchase price and have borrower put money in?

I even got an email from a private lender offering a loan AND the collateral due to the borrower burning through capital and now they are stuck with it. 

If I’m going to use a combination of hard money and conventional (maybe FHA) loans, I will need a LLC for hard money eligibility anyways.

I also have a primary residence with nearly a JUMBO loan at a high interest rate and I own a vacation place in cash (small trailer not worth much money but i also own the land) in a different state that I pay RE taxes on.