If we look at the list of magic weapon special abilities we see that they're divided into two categories, Melee and Ranged, which designate the category of weapon they can be placed on. Some, like, Keen, have additional requirements listed for enchanting, while others, like Designating (Greater), work for all weapons of that type.
If we had a +1 Keen Dagger, when used as a thrown weapon would it have a critical threat range of 19-20 or 17-20?
Similarly, if we used Empty Quiver Style to make melee attacks with a +1 Greater Designating Composite Longbow, would it still grant allies the +4 morale bonus on melee attack rolls and a +6 morale bonus on melee damage rolls?