For what it’s worth, I do think OCIS is worthy of switching to if you don’t make use of all of the various apps Nextcloud can do. OCIS can hook into an online office provider, but doesn’t do much more than just the cloud storage as of right now.

That said, the cloud storage and UX performance is night and day between Nextcloud/Owncloud and OCIS. If you’re using a S3 provider as a storage backend, then you only need to ensure backups for the S3 objects and the small metadata volume the OCIS container needs in order to ensure file integrity.

Another thing to note about OCIS: it provides no at-rest encryption module unlike Nextcloud. If that’s important to your use case, either stick with Nextcloud or you will need to figure out how to roll your own.

I know that OCIS does intend to bring more features into the stack eventually (CalDAV, CardDAV, etc.). As it stands currently though, OCIS isn’t a behemoth that Nextcloud/Owncloud are, and the architecture, maintenance is more straightforward overall.

As for open-source: OCIS released and has still remained under Apache 2.0 for its entire lifespan thus far. If you don’t trust Owncloud over the drama that created Nextcloud, then I guess remain wary? Otherwise OCIS looks fine to use.

You use Steam for games on Linux primarily. Independent native games exist as well. Many Windows-only titles will be best run through Proton: Valve’s modified WINE bundle. Other store titles can be configured to run through WINE or Proton via apps like Lutris or Heroic (GOG, Itch.io, Epic Games, etc.).

For multi-monitor: use Wayland. For 2.5Gbps Ethernet NICs, they never work properly on any system in regard to performance, but I presume you are referencing the subpar Realtek NICs not connecting? Depending on the distro, you likely won’t have the driver and/or firmware package preinstalled to make it work.

https://librewolf.net/

A summary from its site and known technical details:

• no telemetry by default
• includes uBlock Origin
• has sane privacy-respecting defaults
• prepackages arkenfox user.js
• relatively well-maintained fork of Firefox that keeps up with upstream
• No major controversies AFAIK

As for Windows 7, nobody should really need to install Librewolf anyway on such a device. No device running Windows 7 should have access to the internet at this point. If you are asking about compatibility intending this use case, you have bigger problems to worry about than your choice of browser. If you just need to view HTML files graphically, even Internet Explorer or an older firefox ESR will do.