Typically I have little to no code in my Frames when I make GUI apps. I usually have a Panel that contains the logic to set up the GUI. This makes it easier to change the application into an
applet or other type of program.
As for the rest of your questions, I don't have much advice off the top of my head.
You should probably mosey over to
the GUI forum where questions like this are more on topic. Also, the experts on this topic will be more likely to hang out there.
Keep Coding!
Layne