I've searched around and found that the backspace and arrow key problem has been a known issue on 1.x versions of SQL Developer. In that version the fix was to reload the keyboard Accellerator bindings in Tools->Preferences->Accellerators. However, the Accellerator dialog isn't available on 3.2.2 version. Is there any other way to fix it? I know on some Macs, the keys work fine.