One of the benefits of using & is when you need a specific number of words for a trigger (no more and no less). Using matchtext of
!ban & for example would require that the person include a nick/address or at least *something* after !ban because that would be required. It would also prevent someone entering too many words if you don't want to handle more words.
Using the ? wildcard is not necessarily as helpful in most situations, but it can still be useful. For example, if your trigger was
!gray, you might want to also allow for the alternate spelling of
!grey. For that, you could use
!gr?y as the trigger.
There can be any number of uses for either wildcard. You'll know them when they come up. If * works fine for what you need, then that's all you need to use. If you get to a point where you need more control, then the other wildcards may be useful for you. And, if you need even finer control, there is always regex.
