We didn't trust them, so we denied them the right to tax income period.  

You'd need more insurance and the damage would be a hassle.I'd assume there would be parking issues - maybe you can deny just based on parking issues?

So, I'd deny them if at all possible if it was me, and since you can deny them based on credit, I say "Hallelujah!"  

Let me take back one part here... the short rent would only be denied by LTB.

You want tenants with something to lose, or you have zero leverage.I'm glad you denied them.  

Being listed as an additional insured does absolutely zero harm to you, however it does protect you in the amount of the liability coverage on that policy and it also pays all legal fees up to the point when the limits have been paid out on the policy or the claim is denied.

It's hard sometimes to instantly deny them based on prior evictions, I understand life happens and things like that. 

When I called the police department to request an officer’s presence at the court hearing, the same person denied giving me the aforementioned feedback and said, to quote, “this is not how things are handled”.

One point of my criteria that I learned to include over time - if someone is late, without a phone call and a darn good excuse - denied. 

First I agree with Greg, that it's legal to deny someone who doesn't have a social security number.