Since the key strokes are captured directly by Tk, I doubt that anything could be worked around on the Python side unless there was some Tk option to disable a class of input characters or something. Seems unlikely but I can check with the tcl-mac list.

I should point out regarding 5a and 5b that with the X11 option (as with MacPorts today) using the Apple X11 Quartz window manager server (the default option) is a relatively seemless experience for the user. Clicking on IDLE.app or executing bin/idle in a shell causes the Apple X11.app to launch automatically and the expected IDLE windows appear alongside the user's existing (non-X11) windows.  The main difference is that there is the look of the windows and that the menu bars are in the X windows rather than in the normal OS X menu bar at the top of the screen (that menu bar is for X11.app).