But why force the move because of what you perceive as a potential inability for a tenant to fulfill the rental agreement terms before giving them a chance to prove otherwise?

If you have a ton of prospective tenants clamoring for the property, you might as well hold on to the $3k and approve one of them.As always, be careful that you aren't running up against any discrimination laws or could potentially be perceived to be.

Another factor is that while everything is going well, it may be perceived to be cheaper to self manage.  

If you learn what things will provide more perceived value in the eyes of your tenants, higher prices will be justified accordingly.

I also have this mind frame of feeling like the tenants are doing me a favor by living there and paying what I perceive to be a "high" rent.

However, that heart has also given me a majority of tenants who perceive me as fair, expect an annual rent increase, pay on time, and refer friends who are looking to rent or buy (I'm also a real estate broker). 

When I finally put a stop to it all I was the bad person and there was some serious friction because I was perceived to have gone back on my word.

If you perceive the risk of knowing about this behavior and doing nothing about it as low, then do nothing.

They view the world differently and react differently to things they perceive as transgressions in their space.

So, put up your barriers and if they assert some right against your property, then deal with it.I would not put up "No Trespassing" signs, myself, as that might be perceived as hostile to the neighbors.