The hassle of showing the property to prospective tenants; including the no-shows, clearly unqualified applicants and clearly undesirable applicants.2. 

A shift in market value could leave you stuck in a undesirable loan.

I am also confident that I would be able to get parents to co-sign, which I think is a good idea because besides having the security of locking the parents into a contract, I think it would weed out some of the more undesirable potential renters.

Two things to consider:- before rent control in my market we got rid of undesired tenants by raising rent to above market rate.  

Any factors making the area undesirable for this type of investment?

And what other dumb, restrictive rules will this HOA pass going forward, making it more undesirable owning rental property under their "rule"?

I didn't mean to give him false hope or put him into an undesirable position.

So while I agree with you about using the increase to drive out undesirable tenants.

No we can not simply replace undesirable/bad tenants in a nanny state.Here is another example of Ontario codes- Ontario human rights- landlords may not use a income scale to determine a applicants ability to pay.

Yes, the crime rate is higher than other areas, the schools are not as funded, and there are many other issues that might make these areas "undesirable" for some.