Also the lockbox so the downstairs tenant cannot alter the temp for the upper unit.

Thanks  I'm reading between the lines, but what I'm translating here is that the tenant is complaining, but you have no evidence that the tenant's concerns are valid.What I'd do is offer to let the tenant out of their lease. 

Not sure if that’s the reason in your area but one reason people don’t like investors is the rapid gentrification of an area which alters the local culture and makes it unaffordable for the folks who grew up there/lived there for generations to stay.

I find it hard to believe any insurance carrier worth their salt would not alter the premium based on an increased element of risk.I personally would have the seller deliver the unit vacant. 

I understand the differences in lifestyle, but how does that specifically translate to screening criteria?

Sounds like everyone has had a few bad experiences and either moved on or altered their lease to ensure it doesn't happen again.I'm going to stick with dogs and cats to not limit my pool of applicants. 

Due diligence should not be altered for the convenience of the tenant.Good on you for finding a cash flowing rental property

A housing provider should do everything s/he can to assist, but s/he is not required to make changes that would fundamentally alter the program or create an undue financial and administrative burden.

I don't know what that means, but I'll translate it to, "Cuppa tea?"

The problem with gifts, as I see it, is that it alters the relationship from professional to personal.