I'd also install some security cameras (not in his unit of course) and catch him in the act. 

(Probably what I’d invest in before installing the cameras).

They had a camera in the backyard that switched on red frequently am I’m assuming was motion triggered.

Install some cameras, send a notice to all saying tampering with smoke detectors isn’t allowed.  

Good idea about inspection with a camera/video.

I need money to buy myself time: cooker, housekeeper, gardener, shopper, full time nanny for kids.

I wouldn’t be afraid if you got three years proof of good cash flow and you put cameras In .

I guess I got the idea from other local area businesses (mainly bars) that have done the same thing - anytime a patron is caught on security cameras doing something egregious and causing damages they will post it out on social media - usually the person is quickly identified and they end up making amends and paying for the damages.All I'm seeking is our money back without having to lose half of it to a collections agency and secondly for him to knock his bullying off. 

It'd be tight, but you could cook dinner while still in bed...https://www.homes.co.jp/mansion/b-9520000416/ The condo is so small the couldn't even fit a camera in it to take pictures of the inside!

The cameras are of all sorts, infrared, you name it and they are capturing the Earth with it.