

In general, Bazzite being immutable just means the core system isn’t modular to the end user to the degree that Arch is. You of course can use flatpaks or appimages like any distro, and there are still several ways to install traditional rpm/deb/aur programs (the usual Fedora method doesn’t work because dnf doesn’t exist). If it’s just an app that doesn’t require significant integration with the OS, the recommendation is to install them into a distrobox container (where dnf does exist) and then distrobox-export [program]
to make them visible to the host system. VPNs need a little more integration so those are installed by layering with rpm-ostree and then enabling the systemd service(s). Layering makes updates take longer to install so it should be avoided when possible.
One of the interesting things about Universal Blue’s images like Bazzite is if you want the benefits of atomic while also having a more custom system than they offer without having to install a bunch of things in rpm-ostree, the process to build a custom image based on one of theirs is apparently quite easy to do and automate, though I haven’t done it myself.
I would recommend against pairing Battlemage with a low-spec CPU. As shown by Hardware Canucks, Hardware Unboxed, and others, Intel’s Arc graphics driver overhead is currently much higher than competitors, which means they’re disproportionately affected by having a weaker CPU. This causes the B580 to lose significantly more performance when paired with low-end CPUs than a roughly equivalent Nvidia or AMD card. At the very low end, the difference is especially stark. In some games, the B580 goes from neck-and-neck with a 4060 on a high-end CPU to losing half its performance with a low-end older CPU, while the 4060 only loses about 25%.
If you’re really stuck with a lower-end CPU, it would be far better to get a used midrange AMD or Nvidia GPU from an older product generation for the same price and use that.