Graham,A few things to remember from an insurance perspective:1. once the Dwelling moves from owner occupancy to tenant occupancy the policy will most likely need to be moved from a Homeowners form to a Dwelling/Fire policy.   

But in other cities that perspective would make sense as long as they didn't add other regulations on top of it.

You have put all I have been learning as a beginner into perspective.

You lowered my stress immensely by looking at this from a simplified business perspective. 

I would be glad to offer you some perspectives on items you mentioned if you would like to discuss and I'd be glad to connect you with some investors I have worked with to get some insight on their experiences.

Possible mass exodus 2.0 but is purely speculation.It’s good to reach out and get others perspectives but don’t get caught in analysis paralysis, your first deal doesn’t have to be a homerun. 

That crack in the basement wall or the maintenance records etc....I would also review what other things you have been told and what was disclosed and look at it with fresh eyes.  

From a tax perspective, you won't have as many advantages as you would as a US citizen, or other foreigners, for that matter, but I've been told that the returns still make the investment worthwhile.

To put this into perspective, this was a $420/month increase x 4 months!

From a lending perspective, anything property with more than 4 residential units OR has non-residential uses (office, retail, mixed use, etc) is commercial.