I would also be interested in hearing from the community on any regulations that I should be mindful of, as well as thoughts on conventional building vs. pre-fabricated / modular.

Any of these out of area developers looking to wash their gains will have a difficult time with the fabric of the areas and the fact that land is limited or was previously industrial.

What you did and continue to do is fabricate reality.

Plaster and lathe and LOTS of wallpaper to remove (thank you fabric softener). 

How can I delicately propose that if he were interested, to potentially sell directly to me and emphasize that we could avoid the realtor fees in doing so? 

By all appearances, this seems to be a FREE site.Niche.com: This site gets into the fabric of the communities/markets.

It is theoretically possible, especially if you reinforce the joist six ways from Tuesday with additional sistered joists and a custom-fabricated angle iron, but it will add a LOT of money to your renovation.

I work in the construction industry as a structural steel fabricator (welder / fitter.)

It was murder trying to get the dog fur out of several pieces of fabric furniture and we had only allowed two or three.

Growing up in the jungle, you can discern the predators, the prey, the fabricators, the set traps, you develop conviction because your survival depends on it, you value people more, etc.