I've had to re-do most of our lease option homes 3-4-5 times over the years with new carpet, paint, stoves that have never been cleaned - since they moved it. etc. 

I hear they've turned some of the old factories and warehouses into condos and offices and cleaned up the park along the canal.There use to be some rough spots (by the old silos) when I lived in MTL ... but that was a long time ago (before your time).

I'll take 4 seasons, a 2500 sqft home on 2 acres for $200K, a down to earth girl, clean air, and 100 yards of open highway in front of me and my V8 every day.  

I think one was an electric car company I haven't been keeping up with it as much as I probably should.

When evaluating properties be sure to make sure they include the basics like: Real Estate Taxes Insurance Gas & Electric Water & Sewage Repairs & Maintenance Unit Turnover Contract Services General & Administrative Payroll & Benefits Marketing & Promotion Legal & Accounting Landscape & Snow Removal Trash Removal Management Fee Reserves for ReplacementsThese items at the very least should be included in any competent underwriting of a property, be it by a broker or the owner directly.  

Are there electrical outlets in the walls in question?

Corrosive to HVAC plumbing and electrical very hard on the Lungs especially for a compromise immunity system, to identify the Chinese drywall go up in the attic and look at the backside of the drywall in the ceiling you will see Chinese printing in red.

The single property building is most likely one water/sewer/gas/electric service.

Has 1 tenant upstairs for 6 years, very clean tenant paying below market rent at 550/month.

You could manage it the popular vacation rental sites and simply find someone local to the area to clean it, check up on it, handyman it, etc.