I was so wrapped in absorbing every bit of information and networking during the breaks.. that I never thought once about breaking my camera.

Our property has security cameras.

I have a few IMDB credits myself (http://www.imdb.com/name/nm2312372), co-founded BeMore Films (though my partner is pulling 98% of the weight), and am on the staff of a non-profit called Veteran Artist Program, where among other things we help to get more veterans in front of and behind the camera.

Not sure how expensive it would be but a job site camera sometimes is useful in cases such as this.

The only thing you might be able to do is have a plumber snake a camera down the drain pipes to see if they can find anything that may be a problem.

I have used my my management co. handyman to do work and got a price before hand, they stayed within that price, I'm not going to say here it was right on, we did go over, but it keeps the price in check and where you expect it to be. from what you described though, that does not sound like 46 hours of work, i would say, maybe 16 hours. i am in the process of trying to figure a way i can keep track of my companies landscaper, and when they are there. i was billed for lawn being cut 4 times at my properties in October, i think i cut my own lawn only once, if that. i cant argue it because i'M not there. i'm thinking of cameras outside my properties.

This is why cameras work great as deterants. 

Also, once you get done with a rehab (new carpeting, paint, etc.) in a unit, do a walk through the unit with a video camera (phone) and date it.

Illegal activity can happen like it does in MF, but if you have cameras set up, it can help to discourage it. 

Document their actions with a small video as I'm at the property often and take this evidence to the police and/or city.You might try a game camera that uses a motion detector and infrared to catch the action.