Re: fancy-splash-screen customize group...

[Richard M. Stallman]

        This is a customization buffer.

        Editing a field's value changes only the text in the buffer.  The
        State button of an option can be used to set or save the value.
        Options are normally saved in your Emacs init file.  See custom file
        for how to save in a different file and help for more information.

       Note: On your display [Example Button] indicates buttons; type RET or
       click mouse-1 to actuate one.

Some of your changes are ok with me, but some are not.  You introduced
a passive sentence; please avoid the passive voice whenever that is
reasonably feasible.  Here's what I think is best:

        This is a customization buffer.

        %s shows what a button looks like on your display;
        type RET or click mouse-1 to actuate a button.

        Editing a field's value changes only the text in the buffer.
        To set or save an option, use its State button.
        Options are normally saved in your Emacs init file.
        See custom file for how to save in a
        different file and help for more information.

Regarding

    The "State button can be used" since there are global buttons too. 

They exist, but we are not obliged to mention them here.
This text is simpler if it does not mention them.
Remember, in writing documentation, completeness is NOT the goal!

    If others to not agree with me 
    however, I have made [Example Button] a real button (that just says "You 
    clicked the Example Button").

That is clever.