So the city will pick up garbage for Multi-family units.

Not all inspectors deal with the city and understand/qualified for DIHLR requirements, make sure to get inspector that does those.

My wife and I are just about to jump into the real estate investment arena with a single-family home in our neighborhood that we hope to successfully manage as a rental property.

Doesn't cause trouble for the neighbors, with the city or the police. 

At this time I would Sell two of my rental houses in order to Buy my friends two houses, on the lot next door, in a bad neighborhood, because I can get them for $30K under Retail, after a new roof and electric.

There are a few "loopholes" if you will...1) The association approving the lease could be considered a form a discrimination or "first right of refusal" which in some states/cities is against the law, regardless of what the CC&Rs say for the Association.

Everyone there stuck around for the last property, which was a 1900 sq ft  home, built in 2004, assessed at $210k in a nice neighborhood, at auction due to unpaid HOA fees.  

Also, from what I have gathered (which I may be wrong), the better cash flowing properties seem to be in the less desirable neighborhoods here.

Hi Parker,Welcome to the Tampa Investment market (#2 city in the country for investing in real estate actually).

Also, are there any back taxes on the property you would have to pay for, any backed up bills that are due to the city/utility companies?