Is there a way to fix gimp on OSX to solve the xwindows focus issue?
Solution 1:
I believe that 2.7.3 and later have a Single-Window mode that may solve your issue. I'm not sure how you have GIMP installed on OS X, but you can probably get 2.7.3+ using MacPorts.
Solution 2:
If you can't get 2.7.3 to work, I also found that in GIMP 2.6.11 there is an option in
X11 preferences in the "windows" section for "click-through inactive windows". digitxp's solution is better but 2.7.3 crashes for me on Lion any time I try and use the text tool.