Not to mention the inter-personal relationship drama.If three or more unrelated people want to rent from me, I require each individual to earn at least 2x the rent.

However, am I legally responsible for their behaviour as they are all adults. 

All we have are basic markers in a persons past to measure by and I will not be forced to gamble my business on their future behaviour.

The tenants are attracting the rodents with their behaviour.

These tenants have a behaviour of not alerting you when something needs fixed until it is dire!  

Having a deep interpersonal position and stance, when working with my buying agent, he knew how to bypass barriers that many realtors fail to realize.

It is the behaviour, you have gone 10 month living together ok and now she is getting aggressive, you are so much more at risk from a tenant in your house.

It doesn't matter if he loves the place, tell him you are not dealing with disrespectful behaviour and he can find another place to live. 

He was on his best behaviour the whole time because he knew that if he blew it he'd be out.

I have faced this more than once and had to apologise for my behaviour but I have always accomplished my goal in getting rid of bad tenants.In this case it was not necessary and had I been in this situation it would have been resolved as it was.