• I don’t see anything in settings or in the official plugins but there seems to be some plugins. Some seem to be to just search and not the pre-roll trailers.
• There is a subtitles plugin that works well. It is not as cleanly handled for my tastes. You have to search for it on the media landing page. You cannot download and select while playing your media.
• You can filter and then sort
• I do not have experience to answer that
• There is a delete media option. I am transferring a large amount of data right now and cannot test if it deletes it from Jellyfin or entirely.

Not OP, never used Plex, I make accounts for people and send them the address, username and password, that's it.

As for the work I had to do, I run Proxmox so I copy pasted a command from the PVE community scripts, and set up a reverse proxy.

I have Jellyfin instance open to the internet. Not many people use it besides me (and even I use it seldom for now) but I have like 3 people beside me that have tried it out.

I am not sure if there is invite capability or anything. But the way I did it is just create logins and basic passwords for my friends and family and tell them that they should change it upon first login.

As for streaming - I did watch couple of movies outside home through android app and had no issues with anything quality or connection-wise. It just worked.

I haven’t set this up myself as my internet provider doesn’t do a public IP address per customer. I never even corrected it with plex.

But as far as I’ve heard, the difficult part is setting it up on the host side with tailscale. From your dad’s side, it should just be entering your IP and then the user/password.