It is possible to make just some tabs focusable, for instance the first 3 of 5 tabs? So that when changing tabs with the left – right keys, the non-focusable ones to be skipped (to be displayed only by mouse clicks).
All Swing components use Actions to handle key events. So you can replace the existing action with a custom Action of your own.
Check out Key Bindings to see the Actions that are defined for a tabbed pane.