Disclaimer: I can only skim the surface of various highly complex rules I mention below.

As others have mentioned, theming is very important.

This could also be a good opportunity for that 1031 exchange mentioned in your original post (since it doesn't sound like the timing may be 100% for the primary residence exclusion), but only if you want to acquire a similar rental/investment property.

They all mention that my business plan seems rock solid and they buy into my numbers. 

Like they both mentioned, there is some amount of consideration for your life and family.

Last thing I almost forgot to mentioned that lenders can lend you between 75-90% of your loan to value.

I like how you point out the "technical" elements at play by mentioning the demand for MBS versus treasuries. 

I still have a little more than three weeks left Yes, and the DIY sites are mentioned in the blog post I previously linked.

For good areas to invest, check out Seminole Heights, University Area, Town 'N Country, and East Tampa, to mention a few.

I would not approach it from the standpoint of I want to build container homes and then look for a site, I would have a site and think about what the best use of it would be and if it happened to be container homes then go for it.As John mentioned above appealing to the masses is the route to success here IMHO