the first command will take too long (and will be very obvious that something is wrong if it takes forever for ls to actually list everything), better run it in the background with &

to be super pedantic, the right picture should say $x \mapsto f(g(x))$

some comments.

• both are absolutely fine for a university laptop, though very different.
• NixOS is more stable. It is almost impossible to brick it, you would have to delete every working old generation.
• nixpkgs is like arch repos plus AUR together. nixpkgs is actually one of the biggest repos if not the biggest repo at the moment. so no problems there.
• i mean, this is like highly subjective and my own opinion: go with NixOS, it’s just a cooler OS imo and your system and your abilities will only get better with time. and it’s fully reproducible by design, so almost every bit of work you put into it will be worth it, in some sense. i also believe that NixOS will become much much more relevant in the future. bigger community, better documentation, more resources!
• …unless you don’t want to put a lot of time in it in the beginning. it will most likely be really frustrating and it will distract you from other dtuff you want to do on your computer. like just getting browser email editor etc. you will have a setup no problem pretty quickly. it won’t be more than just puttung the programs you need in your systempackages. but then you realize you need vpn, or a dropbox client, or some audio setup, and other stuff, and before you know it you are spending hours and hours or weeks trying to find out how this works… this is, i would say, the major “downside” of NixOS conpared to arch
• if you can afford trying it out and then switching to something else and starting over again, try out NixOS!

well, a standalone WM will usually have less code than your usual DEs, but they also can be less secure in the sense that they might not come eith built-in security features. if your screenlock is buggy (it crashes or it lets you use WM shortcut key combinations or something), that can be a problem. or other stuff regarding saved passwords and keys etc must also be done by hand then usually and depending on if you know ehat you are doing either it works well or it is less secure than a built-in feature of your DE.

also, even though you are right that bigger applications potentially have more attack surface in general, the big DEs like KDE Plasma and GNOME might be (correct me if i am wrong) tested for security more than smaller standalone WMs. but i still tend to feel “safer” when i am in control of everyrhing and the DE doesn’t do all kinds of things automatically in the background.

reading your comments, you like to say that someone has “missed the point”.

well, my point is, you should not ignore the DE. i mean, you can, if you can bypass the login as is, sure. but from a user perspective, you should not ignore it, because the DE is a potential security risk. e.g. if your screen lock crashes and whatnot.

sure, yes indeed, your DE can be as secure as you want and it doesn’t matter if your underlying system is not secure. and yes indeed, with any non-encrypted drive, you can just mount the drives on another system (e.g. boot the computer from a USB drive). that almost goes without saying imo, and of course that’s why an encrypted drive is recommended.

the question is, how easy is it to get to the stuff with an encrypted drive when the system is booted and the encrypted drive(s) is (are) mounted? it is not that easy. and there, the quality of your screen lock setup is the biggest risk factor, usually. if you can crash your DE/WM somehow, if it is not setup right with your display manager or something, then you might be able to get into a login (and interactive) shell of that user (maybe because it is the parent process of your WM that you started with startx).

if you “allow” your potential attacker to reboot from a usb stick, then it is obvious that your DE doesn’t matter at all pretty much.

i don’t really get what people mean when they say this…

when you get tty you still get no access, you need to log in as always. a DE/wm/any x11 session/a wayland session (even though wayland is more secure probs?) should pretty much always be less secure, as depending on what state it is in, what features it has, or what happens when certsin components crash somehow, you can more easily “hack” your way in that way than via doing a “ctrl+alt+F-key”. so i don’t get the whole “get tour mind blown” thing there, i have heard it multiple times.

or am i missing something?