I believe most places charge a 3 percent fee or more

The obvious answer here is to somehow get some income and start paying down the credit card debt. 

I am not seeking to charge each tenant, only seeking to remotely monitor each buildings water usage to identify costly waste/problems early as possible.

•After 3–6 months, apply for tier 2 business credit cards (e.g., Capital One Spark, Chase Ink).

They keep any profits above 12% and it appears they charge about a 2% fee plus a couple other nonsense items (based on my very brief skimming through some info). 

As Sean Wagner mentioned, the city of Chicago has adopted their own regulations on charging what's commonly referred to as a "security deposit" you need to do it another way. 

I think the charge is fairly nominal from what I have seen.

You can always charge an air and surface scrubbing fee from their security deposit after they've moved out. 

So, you may not have have the ability to increase rents because Section 8 limits how much you can charge, which may not keep up with inflation.Not everyone has Section 8 issues as my clients had, but you will more likely to have more problems than with non-Section 8 tenants.Multi-Family vs.

I seem to remember that I didn't even have a business card until then either.You are VERY late to the game to be making these decisions.