Only realistic way IMO to earn money transacting real estate with little funds.

I think realistically, your cap expectations are a bit too high for Florida.

There is a possibility that if I hold onto the place for another 5-10 years that I could make $400-800k in profit...sounds crazy but totally realistic if uptown values ever get closer to downtown ones.

Realistically, I would probably only be contemplating nailing down a tarp if either a big tree branch or trunk fell on it (in which case I'm probably in for a new roof anyway, or at least major repairs), or we had a tornado or really strong winds (again, new roof is likely).The only roof problem I've ever had on my personal residence is when I first bought this house; part of it had been re-roofed on a DIY basis. 

Know what's realistic then go beyond it!  

I would have advised you to qualify the seller to see how realistic they are in selling the home for a price that works for your business model.

We plan to bring it down to more realistic 50-55% of gross income.

Your goal seems realistic and feasible.

-What is a realistic timeframe to "break even", then eventually be purchasing our own homes, without investors?

So I would not just go off of a cap rate, but off of the actual (hopefully realistic) numbers that I project for a given investment.