I assume it’s possible to disable Wi-Fi in your home and still find devices with their own internet access within a certain distance to locate any phones or tablets they might have acquired and brought home

Limiting access to the internet

Wi-Fi - just unplug the Wi-Fi router. When I was a teen I had friends who would always disconnect from games at certain times. Their parents would turn off the Wi-Fi and if my friends turned it back on their parents would take it to their bedroom with them.

Phones / Tablets - What child under 16 is on their own phone plan? I would be surprised if the mobile providers don’t have controls where you can turn the data off.

Other people’s Wi-Fi / hotspots - I can’t think of a way to stop this

I have never had an issue with properly named files.

Some tools to help with bulk renaming.

Krename

Link - https://github.com/KDE/krename

Useful for bulk renaming uniform files. I often use it to add the season when the file names just have the episode number.

Filebot

Link - https://www.filebot.net/

Great for renaming messy files. You can match the show name then it will try to get the season, episode and episode name

MediaElch

Link - https://mediaelch.github.io/mediaelch-doc/index.html

Excellent for pulling the metadata for a show into local nfo files.

Once you have the show name, season and episode number you can scrape TVDB or other sites for the episode data, thumbnails, actors, posters, etc

I then have Jellyfin use the local metadata that MediaElch has created.