So a few points I want to clarify, FDIC insurance is for bank deposits and won't have anything to do with a credit card so don't worry about that terminology when you're searching.As far as building a relationship with a bank I would say it is more important if you don't have good credit and want favorable terms, in your case with good credit it shouldn't make a world of a difference. 

The rest pay by check which takes up most of my time (3-4 hours each month) depositing them.

Its alot cheaper than an eviction (If it works) I would start with the amount of their security deposit!

In terms of qualifying income, lenders will use 80% of business deposits and 100% of personal deposits and use your full W2 Income.

The Code enforcement of the City sent a letter to say the tenant needs to vacate and the owner must reimburse for relocation fees in the amount of 2 months rent and the deposit.

Is the deposit less then 1000?

After giving this vendor a $15k deposit I started to get some weird vibes about them and called the utility company.

What about security deposit accounting?

Stop showing it...waste of time and effortYour only leverage is to start discussing how much deposit will be held if there is a lot of cleanup after move out...damages etc.

Your policy is "last month's rent plus deposit."