I'm underwater with my mortgages and credit cards and bills.

Risking your house on these kind of moves can become a literal house of cards as you scale.

The 14 day trial requires your credit card information.

So I used 0% interest for a year credit cards to pay for cap ex things that popped up or a rehab etc.

I know many folks that started a business with just a business card, telephone, a vehicle and ambition. 

That's a house of cards ready to fall down fast. 

I called Home Depot, they told me to dispute the credit card charges so I did.  

sometimes to reduce borrowing costs, I'll use a hard money loan solely for the purchase, and then pay for the rehab in cash or use a 0% credit card (I don't recommend that for new investors!)

Depeding on the amount get a credit card that has no interest for 12-18 months. 

If i can invest it and make a significant better return after tax than paying it down I would do that but in this instance you will never be able to achieve returns that match credit card debt.