Long-story-short, I had a house meeting with everyone and signed extra contracts stating that any further infractions were grounds for not renewing their lease the following month.  

Yes Chris, that's what I'm saying and not so gleefully about it, the real trick is cover the big stuff and when you have a small infraction do an on the spot correction or take immediate action to cure the issue, then they may not write you up as badly as they might have. :)

They could call the cops or the building inspector for any and every little infraction.

People lost money.In our legal system, enforcement will be much like everything else, a slight infraction with no harm done may be one thing, repeated violations with damages will be entirely different.

This website found ONE infraction for him.

I hear all this from the cleaning lady we employ and its difficult to determine where the line of overly worried gossip and true lease infraction is taking place. 

Not disclosing that fact is simply another fraudulent act and inducement made to the contrary is another infraction.

Advise your tenant to keep a written journal, with dates, times and 'infractions'. 

go to the Planning and zoning office to find history of infractions, any prior inspection reports, Utility history. 

We actually terminated their lease and we don't have to cite any specific reason in NC, we just have to give 7 days notice, but we did let them know that they had three clear lease infractions. 1) Drugs are not permitted 2) they were smoking on the property/in the house and 3) their renters insurance had expired.