-8

I've been a KDE user for quite some time now and since the beginning I liked closing windows with [CTRL]+[Q] instead of [Alt]+[F4], I think it was the default back in what used to be called SuSE Linux Professionell.
Nowadays, however [Alt]+[F4] is the default shortcut for closing windows and [Ctrl]+[Q] is used for quitting programs.
Each time I install KDE, I now change the settings to the following:

Close window: [Ctrl]+[Q]
Quit program: [Ctrl]+[Alt]+[Q]

While this might be considered to be only a personal preference, I have tested these shortcuts with many of my family members and friends and asked them whether they preferred [Ctrl]+[Q] or [Alt]+[F4] and most of them said, they'd prefer [CTRL]+[Q] as it is easier to use (The space between Alt and F4 is much bigger!).
Another advantage of this alternative is a better consistancy: It is a more natural way to "emphasise" one's will for a program to be closed if you just add another key to the default close-window-shortcut instead of using a complete new shortcut.

So, my "brainstorm" proposal is to change the default behaviour of KDE (i. e. the default shortcuts) as stated above.