We actually had all these back in FFXIV 1.0 - there was a 'throwing weapon' slot that you could equip things like bombs or boomerangs, the drawback was, these were a consumable item so once you used the stack up you had to get more. Needless to say, that was one of the things removed in the changeover to ARR as part of a simplification of the battle system, so I don't think we'll see a return to using them I'm afraid.
