So your debt is currently $3000 per month and your property earns you $1000 per month? 

It would be better to open a new card with 0% interest on balance transfers, move your debt to that card, then pay it off like a mad man before interest is charged.Your scenario indicates you aren't financially disciplined.

I agree with @Shawn Ackerman I would start applying the cash flow to debt pay down.!

Lenders usually determine whether properties are lendable based on the debt service coverage ratio. 

And you do not technically have to replace debt. 

It's debt you'd still have to pay back, but at least you will not touch one of those two amazing interest rates. 

Less risk as far as a debt note, that's true, but debt is not the only risk to be managed.

If you don't have the extra cash, can you get creative with a private lender or partner stacked on bank debt? 

THEN, I plan to purchase the second home using a FHA or conventional loan (3%-5% down), for which I will likely pay the monthly cost out-of-pocket, maybe with some rental income support if it is a duplex.My concern is, I do not want to spend my savings or weigh down my debt-to-income ratio so much so that I cannot qualify for and pay the down payment and closing for the lending on the second home.Questions: - With the first home being multi-family, 75% of the rental income (or potential rental income initially) will relatively either maintain or boost my debt-to-income ratio from lenders' perspectives, right? 

In my case I sold off appreciated properties in a location I deemed as having limited future upside, and used the proceeds to eliminate all debt on the better located prime properties I wanted to keep long term.