I think you are missing the most critical features, stability and support. You need whatever distro you pick to be solid. No one cares about the file system or whether it is immutable or not, your users need the computer to work when they use it, and nothing else matters.

You also need to be confident you can update and upgrade safely and easily, any risk of a broken update will make your life a misery when that happens.

Kickstart support, or some form of automated deployment will also be extremely valuable so that you can easily redeploy broken boxes with minimal effort. And some form of remote config/admin will also be extremely valuable. You dont want to have to do updates manually one at a time.

I would pick a general purpose commercially backed OS, so that if you need it later, you can pay for support if there is a problem. And you need to write some basic usage guides, because no matter which distro you pick, if its not Windows, your users will complain when they cant do X the same way it works on Windows.

Look at what schools in your area are using. Pick that.

If I had to make a recommendation outside that one: RHEL. You’re literally their target audience.

Just wanted to say your English is wonderful.

I’m going to say Debian or RHEL. Both are extremely well supported by software and very stable, but you’d get administration benefits with RHEL that you would be missing with Debian. Since these computers are public-facing I’m going to STRONGLY recommend against smaller distros like Zorin or Manjaro.

Debian and RHEL are proven to be stable for professional work. Debian is especially notable for being on the space station. RHEL is used by basically every company that uses Linux in an enterprise environment.

I’d use fedora atomic, specifically ublue, because you can fully control what the os is.

1. It installs updates while it runs and at the next boot it boots into the updated image. If an update fails, it boots into the old image.
2. Most people don’t know WM. Use a DE. It doesn’t matter which one you use KDE or GNOME. Both are stable and solid. It’s up to you. Maybe choose it based on the apps you use.
3. Other questions are redundant.
4. https://universal-blue.org/ https://github.com/ublue-os if you’re interested, use https://blue-build.org/ and your own OS is ready to go within minutes.

Package update frequency:

With Ubuntu and with Debian there is also LTS (Long Term Support) to choose from. For Ubuntu this is five years for the default Ubuntu. I believe it is three years for the community flavors (Kubuntu, Xubuntu and so on). Personally I find the pushing of snaps and Ubuntu Pro by Ubuntu somewhat annoying and confusing, so I’d for Debian at your school.

if the lab users aren’t adults; i would go with an immutable distro

You word structure is a little odd but I think I can figure out what you are trying to ask.

If you looking for desktops I would focus on stability and reliability. For the desktop you could use something premade like Linux mint or you could roll your own with custom Xfce4 configs.

The real question is how you are going to manage this. I assume you have some sort of active directory environment but your group policy will not work on Linux. I would setup Ansible so that you can manage all the desktops in one place. You can create a Ansible playbook that domain joins the machines and then sets up the system.

I would probably do debian 12 with kde, xorg, ext4. Not familiar with debian edu though.

Opensuse tumbleweed. Its rolling release and gets lots of packages and is pretty stable NASA uses opensuse for there computers. I run tumbleweed on my laptop and btfs is really good and i havent had any issues minus one time i forced powered off while it was updating and it broke zypper. Plus side tho is the live boot can "upgrade an install and fix things like broken package managment. Aswell as opensuse is based off of rhel so package support is really good

Linux Mint

Kubuntu and Fedora KDE are probably the safest options. Linux Mint (Cinnamon) should also work. I’d go with KDE, as it looks and feels similar to Windows, which will make it easier to learn for new users. Cinnamon is another great choice for new users. The file system doesn’t really matter, ext4 should be fine.

I’d go with a stable distro, like Debian, or Mint if you wanted something that’s also rather stable and easier to use (Ubuntu underlying structure has a lot of fixes/changes compared to debian).

OpenSUSE newcomer here, from decades of Debian and Debian derived systems.

I vote Debian with Xfce4 for the base system with Nix or Guix to let the kids freely install and play with software as required without requiring root. Stable release should be good. Testing release if time and resources to keep up with the updates are at hand.

Along with teaching the kids computers and software, please also consider teaching them how the Debian packagers, maintainers, developers, testers, admins, etc work and might never meet others in the project whilst releasing a great system every couple of years.

Check zorin os, it’s Ubuntu LTS with a familiar look, and wine well integrated. Veyon sw then is probably good for pc control