This is not possible. Corners were done with ags. Actually, now the whole bar is ags, I don't use waybar anymore. But the design is the same

Waiting for Plasma6, will give it a try

In order to figure out, what's Nix, how to use flakes and home manager, I'd recommend watching LibrePhoenix. It's absolutely fantastic guides. His repo with Nix config is also great, it's the one, which I'm gonna take as a reference

Please, give me some time, the repo is messy as hell now. If I were you, I would not do that now. I'm going to refactor the code, make it more modular in order to allow several WMs and themes. I'm also gonna introduce instructions for installing all of this)

However, the best way to enjoy system you use is configuring everything yourself, though it requires some time. In the past, when I copied configurations from unixporn posts, I always ended with dropping them and reconfiguring everything, as I like it)

Not really. I didn't really check how much space other snapshots, e.g. btrfs ones, takes, but now I deleted 630 generations (basically snapshots), and it resulted in freeing 11.5 Gb of space, not much IMO)

On the left, it's the floating terminal with neofetch. On the right - the notification center (SwayNotificationCenter), which can opened with clicking on the bar.

NixOs icon on the left side of the bar opens nwg-drawer, which is shown on the last screenshot)

I use Hyprland with mouse without any problems. Though, I have MX Master 3s, it has additional button, which's mapped to Meta in my case. Also, there's a right click menu, implemented with ags (similar to openbox menu). So, I can open, close, resize and move windows just with my mouse

I love Gnome's look, but this is better.

That's Snusmumrik from the Moomin series)

automated icon theme?

Do you mean smth like this?

Here it is) The original image: link

That's spotfy-player