Unfortunately not, Gabriel. 1031s are quite strict, and involve equal “equity” deployed in order to persevere the gain deferral.That said, if you’re okay with realizing *some* capital gain on boot / mortgage boot, you can pull *some* cash from the 1031 exchange.

Meaning no part of the structure would be in the flood plain, rather built up to the current building code. 

Any suggestions on zip codes and realtors?

There are only 5 houses under $700K for sale in this zip code .  

When we bought ours we had to kick out all kinds of problem tenants, but we remodeled them nicely and are very strict on the type of tenants we allow so everyone feels safe and comfortable living there.

Signage may be controlled by building codes in your area or special signage codes regarding heights, foundations, electric Lighting Etc...

You get grandfathered into the codes that were in place at the time, you get the old setbacks, you don't pay an architect, engineer, city and permit fees, plan check costs, school fees and other costs that will not come with an existing house.Not saying that you can't build new for less than a remodel, but not usually when you add in all the costs above. 

Then i connect it to my locks so that when guests check in, the door code is set to their phone number and it is set automatically.

I had Rental Duplexes and some Houses in South Tampa for 30 years and the kinds of damage and rot you are talking about with the 100 year old side of the Duplex need to be shown to Code Enforcement in case they would consider it a Tear Down structure.

When you get closer to the date you're ready to start shopping this area, I'll be happy to update the appreciation reports for any zip code you're interested in.