>First, I'm not sure what's the problem you're talking about, can you explain in details?
Simple. There is no way for language switcher to use only modifier keys. X protocol itself doesn't support it and workarounds are too complicated (like getting grab on all input and re-inserting messages back).
>Next, what a strange choice for the keyboard layout hotkey, there're plenty of keys on a keyboard (CapsLock, Menu...) that are less used and easier to hit.
That's the default layout switch combination in Windows, so a lot of people have it hard-wired into their brains. I moved to CapsLock, but it definitely was not comfortable.
>First, it's a bad idea anyway, because if I changed resolution with `xrandr` I don't want it to change back when `xrandr` exits.
Duh. I think it's obvious that there should be a special protocol for resolution changing apps.
>Next, Xorg is able to "restore" whatever resolution you configure using Ctrl+Alt+GrayPlus and Ctrl+Alt+GrayMinus since forever.
And they do not always work. Besides, I don't _have_ a gray minus on my keyboard.
...and here we have a wonderful example of X's "robustness"...