My hypothesis is we will not see a vast reduction in heating costs during the coldest dead-of-winter, but will more than make-up for it in the shoulders of the heating season (October - December, March - May). 

However Will u have sufficient equity after 6 months of seasoning to get traditional financing?

After you can demonstrate a track record of successful flips, you should be able to get a loan that will fund up to 80% or even 90% of the purchase price, and sufficient funding for the rehab, up to a maximum of 70% of the real ARV. 

If you do the chances of getting into this type of situation in the first place should be vastly reduced.  

Is a 30 gallon hwh sufficient for a 1/1 im south Florida where the winter temperature is in the 70s?

I have to say one thing though... vast majority of these properties are in need of some serious work.

Yes, you can probably reduce cost of sales and perhaps other numbers but you cannot significantly reduce rehab costs and there will always be surprises which will burn you if you do not have sufficient funds set aside.

It needs to be sufficient to heat the space if you want it for something other then decoration. 

The vast learning potential at my fingertips.

that's the thing I'm actually extremely interested in, as I have a vast network of door-2-door salesmen who make a ton of money but because of the nature of their work can't get homes.Thank you