This will be a panel-type mastermind session

Should I bill the tenants a flat rate per month?

I also have a 2 flat that is under a $100 every month.  

She left multiple flat screen TVs, four laptop computers, all of her clothes, all of her photos, jewelry, and even some brand new rifles!

Mold, basement moisture that rusts the breaker panel, inspection difficulties, etc. 

Also many multi units have a common area electric panel the landlord pays for. 

I would look into that.....Flat roofs suck IMHO.

Management fees vary widely depending on the market and can be anywhere from 20-40% (or even as high as 50% but that's less typical)  If somehow here it's a flat fee included in the HOA, well, score!

Buy an owner occupied 3-4 flat (live for free & learn REI/property management skills)4.)

Petersburg, FL at this moment.