You are used to KDE and Gnome is very different But also KDE is buggy, I dont know how Steamdeck people make it better. If you chose Xfce, you will get a KDE similar desktop but more robust. Xfce can look modern with few efforts. MX Linux distro is a good example of a nice Xfce config.
Doas has a readable config file and it is easier to add an user. To answer your question On an MX install.
Xfwm -> bspwm
Dont remember -> nsxiv
Don’t remember -> mpv
Featherpad -> Mousepad