Text:
I consent to Plex to: (i) sell certain personal information (hashed emails, advertising identifiers) to third-parties for advertising and marketing purposes; and (ii) store and/or access certain personal information (advertising identifiers, IP address, content being watched) on my device(s) and share that information with Plex’s advertising partners. This data is used to deliver personalised ads and content, ad and content measurement, audience insights and product development. Your consent applies to all devices on which you have Plex installed. You can withdraw your consent at any time in Account Settings or using this page.
Soure: https://www.plex.tv/vendors/ (Might have to clear cache)
Can also read about the changes here: https://www.plex.tv/about/privacy-legal/
Yes. It's very easy. It might not have used to be easy but it is for the last couple of years. Dead simple. About a dozen people use my Jellyfin server across TV's, phones, tablets, laptops. None of them are what I would call techies. It's as simple for them as Netflix.
If you have not set up a VPN for accessing your Jellyfin, I would suggest looking into the myriad of security issues the Jellyfin Backend has. Jellyfin has no business being accessible from the public internet