I'm in the position to apply(depending on lender DTI requirement) for conventional financing through the builder at <6% interest rate in this current market.

It depends on what you are looking for. 

Also, I live in FL and will not touch anything UNLESS I can get it at 25- 30% LOWER than the ask, even then IMO its overpriced.

If you have any disagreement with your new business partner, they are in the driver's seat because they are the OWNER living in their HOME. 

Depending on the lender and whether there is assumable language in the mortgage docs, not likely. 

This is where I live.

We currently live there.

There are some exceptions as to when you can get away with a single stair (full explanation below) but you'll see it is not easy to do.I actually used to live in/rent a third story attic space with a single stair, and as a tenant I thought it was fine.

This trend is expected to persist, driven by Birmingham's affordability and favorable living conditions.

As a first-time house hacker you want to maximize your revenue and minimize your living space to make the most.Also, there are 2+1 units which are 2 legal units and a 3rd boarder unit (either in the basement or the attic).