I have done this for a while instead of a debit card. 

Investors are celebrating rent increases left and right but ignoring the fact that, while their tenants can "afford" the increased rents on a rent-to-income analysis, they cannot afford the rents on an income-to-expense analysis, when you include their cars, credit cards, etc.  

Meet other investors and pass your card out to as many people as possible.

We're paying for repairs with a company credit card.

I have business cards, when I ever I see a "For Rent" sign, I will call.

I will have an on site manager but I don't want them to have to be making a new card or something every couple of days because the bar code got smudged or something. 

There's a minimum dollar amount to register and get a bidders card.

Then, I would stop your contributions of $500/month to "savings" and just hammer out that credit card debt. 

I’ve listened to the credit card hacking podcast on BP/BP Money and a similar one from the guys at Choose FI.

Move to autopay, debit/Credit card or ECH.4.