LÖVE

Sure, I can come up with workarounds myself, but at that point what is the point of using Love2D.

Ivan, do you happens to use GNOME on Wayland?
Because I kinda recognize some of them and they probably specific to wayland implementation of gnome, which is can of worms on it's own.
As slime mentioned about icons, this is wayland thing. As far as I understand, wayland doesn't have currently sane way to provide titlebar icon. You need to provide .desktop file with icon for this to work. Even Godot's wayland implementation currently struggles with that, because this is wayland thingy then love.

The Love2D application title is not set by default in the top bar on Linux

Do you mean title as "Mystery Mysteries" or as titlebar with close button, minimize, etc?
If this is titlebar, then yeah, this is again wayland thingy. Some wayland compositors might provide server side decorations so there love window will have system titlebar, while other compositors like gnome don't use server side decorations, so programs themself need to draw this. As far as love appimage go, titlebar there is working. If you installed love from somewhere else (for example, flatpak version from flathub) then that version might not have using libdecor or something like that for having titlebar.

- On Microsoft Windows 10, the window title is completely off the screen after calling love.window.setFullscreen
It is not possible to move or resize the window using the mouse after calling love.window.setFullscreen

As other people mentioned, yeah, this is how this work with pretty much on many OSs. When you make window fullscreen, then you can't move around it and there usually no titlebars (tho, it might be possible that some window manager might work differently)

Thanks and I appreciate the reply, GVovkiv.
Sure I can solve these issues on my own, but unfortunately it looks like these will not be fixed "officially" in the framework.
The bugs I reported above are basically received with immature replies like "fixed it yourself".
The Love2D forums and much of the documentation are not good nowadays so that's why I stopped participating.

Nothing of this is a bug.

About icon thingy.. We still don't know if ivan was talking about wayland compositor that he had used, but seems that wayland 1.37 got released like week ago and introduced https://wayland.app/protocols/xdg-toplevel-icon-v1 this icon protocol, which means there now sane way to set icon on wayland, yay!
Seems SDL already has support for that, aswell as some wayland compositors like kwin (So KDE plasma) and maybe wlroots. So maybe once love 12 will be released with sdl version that supports this, and once other compositors will start use this protocol aswell, this icon issue should be resolved!

(Still, assuming that everything that ivan said happened on wayland)

SDL3's source code just got support for it a few days ago, but SDL2 did not, and SDL3 has not had a full release yet and it's not clear yet whether it will before love 12 is ready to be released. So whether love 12 will support that depends on SDL3's release timeline.

On top of all that, Wayland currently has performance issues with vsync which is stopping SDL3's wayland backend from being used by default (it'd use the X11 backend which would then go through XWayland, otherwise). So it might not work at all for typical users until other fundamental wayland issues are fixed by wayland developers.

Well, at least we one step closer