Multifamily non-conforming use with no variance on file

[Thomas Higgins]

Hi BP community!

We are in contract to purchase a distressed 5-unit property in Columbus, Ohio. During our due diligence process, we discovered the property has no building Certificate of occupancy, variance, or any paperwork on file with the city. The property is located in a C4 district (commercial use not residential multifamily). The property was built in 1960, so it is not grandfathered into multifamily use. 

We retained an attorney and been advised that the property will need a hardship variance to operate legally. He believe that it will be a straightforward process that will take 3-5 months. I have direct experience in other markets with receiving variances and know there are often trip wires or unexpected costs that one can run into.

I was curious if anyone has direct experience with getting variances in Columbus and if there are anything things I should be on the look out for. Some questions that come to mind:

Will we need to update a class C property to the most recent building code?
Will we need to install fire sprinklers or any other large building systems (often a requirement in Pittsburgh)?
Will we have any community give backs such as donations, murals, or affordable housing? 
What are the pentiles for operating a non-conforming property without proper documentation in Columbus?

Not looking for legal advice. I am just looking for your thoughts or experience. We will be sure to get our land use attorney's signoff before we move forward. 

Thank you!