Make yourself a date to go hang out at a Home Depot or similar store and check local pricing for yourself.  

I however, am a general manager at a store of 130 people.

It's on Amazon and the BP bookstore:  https://www.biggerpockets.com/store

Most of the retailers and big box stores are minimum wage employees, possibly being paid commission, who are by no means experts and just want you to just buy a product or buy a product so their commission is higher.

You find a product, you source over seas or buy at stores.

Developers have been able to get around zoning in this way already (for larger homes).How cool would it be to have a tiny home community with a common building, park space and even some commercial space (for say a grocery store a person could walk to?

As a lawyer (but neither a health care nor tax lawyer, so I may very well be in over my head) I took a look at tax court cases and found a consistent theme:  courts holding that real property is never considered to be "merchandise" and thus cannot be inventory. 

I'm talking about storing all information and creating a crystal clear simple  process from start to finish .

This issue though is you end up storing a ton of cash in one bank account that is public facing so if that LLC is ever sued, youre putting a lot of assets at risk. 2.

I was going to the house, going to the home improvement store, and putting out fires multiple times every week.