You could install ZoneMinder and set it up with your webcam. It will do recording and basic motion detection. You don’t have to mess with any docker stuff, it just needs a recent version of Debian or Ubuntu. If you want to access it from a phone, I would suggest using the zmNinja app since the web UI sucks on mobile.

Some actual CCTV IP cameras would be better than a webcam if you can still find any that provide an RTSP stream and don’t require any of that cloud crap.

How recent does the printer have to be for them to do this?
The two that I have are old and the toner cartridges don’t even have a chip in them, so I doubt they could tell if the toner is 3rd party.

One way to find a private tracker is to monitor /r/OpenSignups. I would suggest using the RSS feed so you can get notified of new posts. Most trackers are only open for a short time. Don’t bother with the new trackers that constantly pop up, they don’t have enough users to maintain a good ratio easily. Be sure to get into TorrentLeech next time they open signups, that’s a good general purpose tracker and it’s very easy to maintain your ratio there.

Another way is to get into MyAnonaMouse, Orpheus, or Redacted through an interview and use the invites forum to get into other trackers.

There are unofficial qBittorrent search plugins for some private trackers. If you can’t find a plugin for the tracker you want, you could always use Jackett.

Torrent Galaxy has been rather unreliable since it changed owners. I would keep an eye out for open signups on any decent private trackers.