I'm happy with my full-time job, but assuming that I will buy 1 house a year, after 20 years that license will save me at least 200k (based on the above assumption).

If you’re referring to whether you can use another FHA (I’m making the assumption since you noted 3.50% specifically), then there is only certain situations that will allow you to have a second FHA loan. 

I have noticed from Google maps view that there has been dumping of construction debris over the bank behind the property, which by my assumption, has been this business. 

Where I believe the demand is strong for the product I envision putting there, this assumption is a gut feeling I have developed over several years of listening to small business owners complain they cannot find this type of product anywhere, or there is not enough of it.

Good Lord - I can tell a number of folks are simply making assumptions.

A common assumption among investors is that estimates from a General Contractor should be free.

That's pretty ideal for some private house hacking.While I'm not an attorney nor specialist in the law, I think we can make a few a assumptions:1.

Also, I made some assumptions to your original post that I should clarify. 1) Do you have equity in the property you can draw on?

You must make them think they are correct in that assumption 

In that case, you have to make some broad and conservative assumptions to protect yourself.