The fan ducts are in the Printables link. They are designed for the rod system so if you can find 10mm rods long enough for an Ender 5 Plus it should work.
It's much easier to install Linux these days than it is to install Windows. And with KDE Plasma the user experience is really similar. As for the distribution I would suggest OpenSuse as that has very little requirement for terminal commands, they've packaged GUI elements in the whole distro.
As for Tumbleweed vs regular, that's up to you. I'm happy with Tumbleweed.
I'm in my late 30s and feel that way about the schools I went to. I studied chemistry and while some of the material was good most of my grades were about teacher pleasing and completing arbitrary assignments.
They cared more about layout and formatting than about actual content in project reports.
Edit: I think the main purpose of higher schools is not to learn but to prepare you for corporate life. Accept whatever task is given no matter how stupid or wasteful it is.
Also don't challenge authority because your grades will suffer and if you do it too much you'll fail.
Or bad planners that expect us to do overtime for their mistakes.