Not because we're smart...but when you keep banging your head against a brick wall you eventually figure out a better way :) 

The easiest way to know what is smart and what is not is to do a market survey of that area. 

Definitely seems possible but if the landlord is smart he will allow you to prove concept, thank you for your services when your lease is up, and then set up his Airbnb.

I will likely replace some of them for now (broken, missing glass).

I look at all those I interact with in this business and their is one theme .. most if not all are charismatic , pretty good sales men and women and or pretty educated and smart..  

That would be a very smart move out there IMO as prices are high.A real estate class is what you need to learn the basics of real estate before you begin dabbling in the investment side!

I thought I was being smart.

There are some very smart people who are better at finding others than my team.

You'd think he'd be smart enough to realize that just mere fact that I'm having the house painted at all will bring up the value on his house by proxy.

I actually think it is a nice feature and would place a narrow entry table (google narrow entry table) against the wall when you walk in.Not sure what the rest of the large room looks like but it seems the wall creates a space for a sofa or love seat against the wall without exposing the back to the entry door.For the opening you could look for a framed piece of stained or art glass and suspend it from wires top and bottom if you don't like the open look.