That is true. But paying for commercial software doesn't free you from having to maintain said software. So while some software might be easier to maintain than other, I think it is fair to just compare the license prices if you have no additional insight into the organization and how their IT operates.

I think you'll find your experience here is outdated. There are a few good tools for managing Linux systems - puppeteer is one. What sorry if features are you missing?

As for Samba, Gnome has good client built in to the file browser. But I'd have to ask why you're using Samba at all. There are much better network filesystems in the Linux world that don't come with all the legacy cruft and undocumented idiosyncrasies that are part of the SMB protocol. They're harder to set up on Windows, but that shouldn't be a problem if you standardize on Linux.

Oh, KDE is much more than a desktop environment.