In the structure viewer, if you press enter, it goes to the structure whose name is in the string gadget. It would be better if it went to the structure that was highlighted in the listview. This would allow you to type not the entire structure name, for example, you could type only console_s to see the CONSOLE_SCREEN_BUFFER_INFO structure.
Also, it would be good if backspace behaved like the back button.
By the way, I think that whichever gadget had focus before you pressed the back button (listview or string gadget) should still have focus afterwards, and that after you hit back the name of the selected structure should appear it in the string gadget.