Lots of questions! Combo boxes; gtkrc; shortcut keys

[overbored <overbored overbored net>]

1. I have installed Gaim, Gimp, and Dia onto Windows XP. There's a
problem with all their drop-down (combo) boxes, probably because I'm
using a dark Visual Style (XP's native theme engine). They show white on
white until I hover over them with my mouse, causing the text to turn
black. I Googled and asked in various IRC channels but found no answer
on how to fix this. The only idea I have is to somehow modify gtkrc. Is
this the solution? How should I modify it? (Also, if anybody knows what
widget it is, each element in the Diagram Tree in Dia is white on white
unless it's selected.)

2. I have no idea which gtkrc(s) to modify. I found '.gtkrc', 'gtkrc',
'.gtkrc-2.0', and 'gtkrc-2.0' in the following locations:

C:\cygwin\home\Jono\.gimp-2.0\gtkrc
C:\Program Files\Common Files\GTK\2.0\etc\gtk-2.0\gtkrc
C:\Program Files\Common Files\GTK\2.0\share\themes\Default\gtk-2.0\gtkrc
C:\Program Files\Common Files\GTK\2.0\share\themes\Default\gtk-2.0-key\gtkrc
C:\Program Files\Common Files\GTK\2.0\share\themes\Emacs\gtk-2.0-key\gtkrc
C:\Program Files\Dia\etc\gtk-2.0\gtkrc
C:\Program Files\Dia\lib\gtk-2.0\2.4.0\Engines\Theme\gtk-2.0\gtkrc
C:\Program Files\Dia\themes\Default\gtk-2.0\gtkrc
C:\Program Files\GIMP-2.0\etc\gimp\2.0\gtkrc
C:\Program Files\GIMP-2.0\share\gimp\2.0\themes\Default\gtkrc
C:\Program Files\GIMP-2.0\share\gimp\2.0\themes\Small\gtkrc
C:\Program Files\xchat\gtkrc

I was suggested to add the following as a solution to #1:

style "mystyle" { fg[ACTIVE] = "#FF0000" }
class "GtkComboBox" style "mystyle"

I did that for every one of those files, and nothing changed. What's
going on?

I am also curious to know what each of them is for. (So perhaps, in the
future when I wish to change the appearance of a single program or group
of programs, I will know which gtkrc to modify.)

3. Is there a tutorial or intro to gtkrc files? All Google returned were
some gtkrc files, some resources (mainly aimed at devs), and archived
posts answered with cursory references to something called
"gtk-tutorial", which I couldn't Google for.

4. I Googled and found that we can supposedly assign keyboard shortcuts
to various menu items by clicking on the menu, highlighting the item,
(I'm assuming, just hover over them with your mouse), and press the key
or key combo. This wasn't working, but much later I found that this has
been disabled by default. How do I enable it? In gtkrc? And once I do,
won't this conflict with the '&' underlined letters?

Also, how do we create shortcuts to non-menu items (e.g., the shape
buttons in Dia's toolbox)?

5. In searching for #4, I read that you can use something called
"XSettings." Googling did no help because there are so many different
things that go by that name, and it wasn't a program with a site, but I
am curious to know what this is and whether it exists for windows. (I
have Cygwin/X but I couldn't find such a program.)

That's it (for now). I'd appreciate answers to any of these questions. 
Please let me know if any further info is needed. Thanks in advance.