In a way, you can use Intros as 'one shot' vamps, and as a substitute for the 'Riff' capability (but with your own pattern and chords rather than the preset ones). Make them long enough (16 bars, perhaps) and you don't find yourself having to rehit the button too often (pretend you are making a fill call if you want it to repeat).

Another use for unused Intros is extra Break/Fills if you make them one or two bars long.

In the same vein, you can use Endings as mid-song pauses, complete with ritardandos.