The gift should be more like a reward for good behavior.

You insist on siding with an unprofessional and unethical agent simpyly beacuse YOU are an agent and you feel somehow that his behavior reflects poorly on you.

As far as how it might affect my descision making process; I am more influenced by income, credit and past record with employers and landlords as a reflection of their character and behavior.

I am not rewarding bad behavior, I am trying to hedge against my investor losing more time and money. 

If so, I'd pass because that shows a consistent pattern of poor financial behavior and you can bet you'll soon be added to that list.The point is, you should look at more than just the score. 

Thus rendering leverage and other "risky" behavior less of a problem.Buy for value, not price.

I think most buyers can see through that kind of behavior.

I have stopped answering phone calls and resorted only to written communication (for my records) but have noticed a pattern of very emotional and aggressive behavior from this tenant (as well as extremely unreasonable expectations about what the timeline is to have something fixed).

Yep, pretty typical behavior for her. 

That behavior is typically what prompts the beginning to the end.