I once heard from someone that changing outlet faces to stainless in the kitchen can make a huge difference and they only cost a few bucks each.

People like us find it crazier than hell, especially since most of the tiny houses cost as much as real houses. 

To set up a normal LLC will cost a few hundred bucks

Have you considered offering wifi at cost as well?

Can anyone educate me on advantages, if any thing other than cost, a steel building would render?

It is the land value, so even if you put a tiny house on a lot, it would still cost a ton due to land value.By comparison, in my state there is ample supply of land.

If it’s the same cost as an attic fan I think insulation may be the better investment.

For whatever reason, is so expensive to repair, yet the materials couldn’t have cost a fraction of the labor expenses.              

Probably not the cheapest, but good work and good prices: Custom Granite Masters, Victor, 702-413-2457I think the transport will cost a fortune though, unless you do it yourself.

I'm sure the really smart and experienced people will chime in to help you see much more, @Alex Costas, but one glaring omission I see from first glance is that nowhere in your expenses calculation did you consider the laundry additions.