Probably a bad time to suggest the Jellyfin for Kodi plugin (since they removed the network paths in this version) but it's what I use for my main playback device.

All the goodies of playback via Kodi but play state and metadata gets synced from Jellyfin.

Another option of course would be to open the file(s) in MKVToolNix to add and correct the subtitle offset there.

Are you using subtitle sync in bazarr? I don't use jellyfin, but have found that bazarr has fixed most of my subtitles that were not in sync just by enabling the option. I think it's CPU intensive though, so don't do the whole library at once.

1: The official Android app didn’t work?
That’s strange as I run it on a Samsung and Pixel straight from the PlayStore. What were your problems?

2: This is not required as long as the profile is set up wthout a password.

3: This depends on the client and codecs supported by it. Newer phones support most, or is able to transcode. Weaker/older units are not.

Echoing @Bronzie@sh.itjust.works, I downloaded the first party app right from the Play Store on my Samsung. Though I prefer the third party, Findroid, the first party app is good for the dashboard management.

When we launch Jellyfin, we are shown icons for what user, we select the user, and it opens the associated library. Similar to Netflix.

I started using Jellyfin about two years ago now, and have only encountered a codec issue here and there, but I've found it can be worked around by setting playback to another player, like VLC.

1. Not sure what you mean by that. Jellyfin has had an up to date version in the play store for years.
2. Yes every Profile is separated into its own account, that's by design and will most likely never change. An easy PIN option in the local network existed for years. Now you can even login with your phone app by entering a displayed PIN.
3. I remember very few media that i had issues with in the past. Depending on the transcode hardware you have some things can be tricky

Wtf is a Samsung app?

Check out Watchtower! Auto-update your containers. Don’t forget to set WATCHTOWER_CLEANUP to true, or your disk will be filled with old images.

Did you use docker compose file or just run a command to start the container?

Edit: I always use compose files. For that you can do the following:

docker compose pull
docker compose down
docker compose up -d

You don't technically need the stop, but I've found once or twice in the past where it was good to stop because of image dependencies that I forgot to put in my compose.

For running a command directly I found this website that seems to summarize it pretty well I think:

https://www.cherryservers.com/blog/how-to-update-docker-image

You could use a systemd unit file:

[Unit]
Description=docker_compose_systemd-sonarr
After=docker.service 
Requires=docker.service

[Service]
TimeoutStartSec=0

WorkingDirectory=/var/lib/sonarr

ExecStartPre=-/usr/bin/docker compose kill --remove-orphans
ExecStartPre=-/usr/bin/docker compose down --remove-orphans
ExecStartPre=-/usr/bin/docker compose rm -f -s -v
ExecStartPre=-/usr/bin/docker compose pull
ExecStart=/usr/bin/docker compose up

Restart=always
RestartSec=30

[Install]
WantedBy=multi-user.target

You'd place your compose file in the working dir /var/lib/sonarr. Depending on what tag you've set for the image in the compose file, it would be autoupdated, or stay fixed. E.g. lscr.io/linuxserver/sonarr:latest would get autoupdated whereas lscr.io/linuxserver/sonarr:4.0.10 would keep the container at version 4.0.10. If you want to update from 4.0.10, you'd have to change it in the compose file.

no need for docker compose down. pull && up is enough

Also depends on how you specified image in the docker. If it has no version or latest as version it will update otherwise it may be fixed

If you set up using compose and don't have the version pinned:

dockee compose down && docker compose pull jellyfin && docker compose up -d

What's this about? I didn't hear anything about it.

It isn't built in to JF; they just added a framework that makes the process easier. You'll still have to use a plugin to skip intros.