The flipper folks always like to say "you make your money when you buy," meaning that the lowest possible and highest value entry price point is one of the most important things.So let's visualize a single story office building.

My full time job requires me to go to the office in Dallas, TX.

Talking to zoning officers, I find that in some municipalities they are grandfathered in, but in others this exemption ends when the lot changes hands.What I am seeing is a picture of a huge amount of semi-rural land that is frozen in time—impossible to use and therefore impossible to sell.

Can you elaborate more on what you mean by "Commercial" - are you looking for a business-purpose loan on a residential investment property or are you looking at true commercial real estate (office, retail, etc)?

Find a local office in WA and discuss your situation with them.

Their main office is in Columbus, but they are licensed in several states.

I suspect they have a procedure to deal with this and it may actually involve having their inspector just go to the office to inspect files and determine that info themselves. 

It's actually where my office is located. 

My insurance company won’t let me rent my 2 car garage or an office space that I have because it poses a “threat” of a non-tenant person coming onto the property and potentially posing harm to my residential tenants.

Also most universities have some kind of housing office that can point students to common rentals as well as on campus recomendations.