He was an INSIDE dog, hence his behavior not liking being put out for my visit, but he assured me he has never has went potty in the house. 

 I assure you you done want to work with these guys,have  no  professional or ethical behavior.

Past behavior is indicative of future behavior. 

Anyone that's been doing this since before the recession operated in that world, I have not and don't think I'd have been a good fit for that world.I know a few realtors that gave up on lending and became realtors specifically because they could not be competitive in a world that rewards crummy behavior.

I make my RE investment decisions based at trends since human behavior don't change be it now or 100 years ago.

My only challenge is that I am encouraging this behavior.

Omer,Stand by your rental agreement guidelines and in this case I would not personally trust a tenant whom has displayed such childish behavior.

If I see a lot of pictures of wild, drunken-looking behavior in groups, they lose points.After having so many 20-somethings, I do find myself craving some 50-somethings.

In America, small business is being increasingly looked upon as a criminal behavior by both the public and governments and our society is extremely litigious. 

This is not a situation for aggressive behavior -- setting foot into this apartment while this particular tenant is still living there would be considered an "aggressive" move, given the info you have given us and it does not matter what the the law says at this point.