I have a process that I'm doing for thousands of images that I'd like to remove as many keystrokes as possible from.

The process is a loop of:
rectangle tool
* select rectangle
crop to selection
levels > select white eyedropper tool
* select white pixel
overwrite original image (jpeg - bump quality to 100%)
close view (or just "next image" - no confirmation dialog for that)

The starred steps require user input, and the ideal solution would only require user input for those steps (and all confirmation dialogs should auto-confirm). Any steps toward getting there would be appreciated.

I tried to automate the process using xdotool, but I couldn't get GIMP to recognize xdotool's "synthetic" keypresses (see http://gimpchat.com/viewtopic.php?f=8&t=14248). Then, I switched to Windows 7 and GIMP 2.8.14 and tried the same thing with AutoHotKey and got the same result.

I'm using Linux Mint KDE 17.3, which is based on Ubuntu 14, and GIMP 2.8.10, if that matters.

crop to selection can be set as a short cut.
select white pixel can be automated if you know what you're selecting ahead of time like brightest pixel or whatever you can't make a script run half way like opening the levels and click on eye dropper tool for you.

Thanks, that's helpful. Brightest pixel probably wouldn't work, but it could just use the pixel at (1, 1).

So far I'm just rebinding the keys temporarily from Preferences > Interface > Configure Keyboard Shortcuts:
c - crop to selection
s - overwrite original
w - levels tool

Would ideally like to get it down to:
(select rectangle)
(single keypress trigger the rest, go to next photo, and activate the rectangle selection tool)
. . .

Actually, I could work with something that would just batch:

all with no user input, and then I could use another tool that's got better UI for cropping, etc. when working with multiple images.

Much the same, assigning keyboard shortcuts

I tried
A = crop to selection
S = call the levels dialog
D = Save and Close then Open Next File.

which is a script Sequential-processing to close the current file and open the next
see: viewtopic.php?f=9&t=4846&p=182394&hilit=+ofn+file+next+#p60519

Ofnuts has a plugin there as well for numbered files. Easy enough in linux to number files and lose the numbers after editing.