Sort of a blend between real estate agent and escrow officer.

You need to talk to a Banker or Loan officer to go over your credit and see what you have in savings.

My office and my house are just north of Reeb-Hosack2 - I do not have the data to support this but based on what some of the long term tenants in the area are at with their rents, I would say they have increased a lot3 - I would say so https://www.zillow.com/home-values/76576/columbus-oh-43207/4 - There is crime in the area but no more than any other city

Instead of filing them when I get back to the office in the real filing cabinets (Probably going to still file the paper to make sure there are no catastrophes the first year).

You visit the lender to their office, talk to them directly and input the number, don't ask via email.

You could build a flex-space building for the plumbing company to relocate their office and warehouse AND have enough parking and now you get 5-10K a month or more in rent. 

Call around to all the real estate offices that do not provide management services.

Yeah I think a HML like @Logan Singleton mentioned would be a good move to call around or connect with a loan officer like him perhaps to see who would fund those type of numbers, but if you wanted to explore private money there's 100 ways to structure the deal.

How about an office work from home space

My local loan officer said I would be able to get a loan up to $450k, if I rent my current home out and the property, I’m going for is a duplex+.