The proper term is mnemonic, not keyboard shortcut.

The following patch adds the following mnemonics: 

* rotate : angle, x/y center 
* scale : w,h, aspect ratio 
* shear : magnitude x,y 
* desaturate: desaturate.  (wanted to do the main types, but they are enum.)
* new layer: w,h. (wanted to do fill type but they are enum.)
* layers merge: expand, clip to image, clip to bottom layer.

touched files:
    app/dialogs/layer-options-dialog.c
    app/dialogs/desaturate*.c
    app/dialogs/info-dialog.c (support mnemonics)
    app/tools/gimp[scale|rotate|shear]tool.c
    app/dialogs/image-merge-layers-dialog.c

Created attachment 51767 [details] [review]
adds missing mnemonics (and makes info dialogs support mnemonics)

All changes are trivial except to info-dialog.c.
Finding the Spinbutton widget belonging to a GimpSizeEntry is hackish.
I see no way to better implement it though.
Otherwise it's clean.

Eeek, yes that's hackish :) No way this will go to CVS, please use
gimp_size_entry_get_help_widget() (yes, this functions is
probably misnamed).

Apart from that, patching info-dialog.c is pointless, because
it will go away before 2.4.

Also, what is AKUMA?

2006-10-18  Sven Neumann  <sven@gimp.org>

	* libgimpwidgets/gimpwidgets.c (find_mnemonic_widget): special
	case GimpSizeEntry and use the last entry.

	* app/tools/gimprotatetool.c
	* app/tools/gimpsheartool.c: added mnemonics (bug #162541).