This so called plumber also told me in the past that he turns off his tenants heat/hot water when they don't pay, so I know he's capable of this line of behavior. 

The fall/winter seasons are when more aggressive deals are done as sellers are more serious about getting out, you can set your watch to this behavior every year. 

I contact them, preferably face-to-face, and tell them "bad behavior" is not a protected class and we will not consider them for any of our rentals.

Turns out another tenant in the building has suddenly started with the same type of behavior, trying to push lease terms, and trying to dictate when we can send our service guys in, always on their terms, never meeting half way. 

The most useful "trick of the trade" that I have come up with was WRITING down a one page late pay policy that encourages behavior that I want and discourages behavior that is problematic.

This sounded like bad business for me to be in after this i had to do more research and the guy that brought me to that event told me about brian meara i heard things about him he selling this hgh somaderm product another mlm crap that i also heard about going on around here that guy sounds like he bad for business too and i heard he messed around with a few women in his group while he was married such unacceptable behavior if you ask me.

I wasnt expecting this type of behavior from him and I have no video or written records of anything.     

Is this the behavior I should expect from a solid PM company?

I personally tend to think that some people go looking to make trouble, and then they try to get out of the trouble they made by excusing their bad behavior as some sort of "trial by fire" of my customer service skills that I failed.

Note that consumer behavior can be pretty weird.