You should be able to repair broken arrows, instead of losing them forever.
If you can craft weapons in this game shouldn't you be able to make them? Don't know how exactly you go about repairing an arrow. If the shaft is cracked you pretty much have to put the arrowhead on another one (ie craft one). Not like you can duct tape it together.
edit: sorry posted this before I read the entire thread. I just think that there should be no need to repair an arrow. That's what the crafting skill is for. If you can salvage the arrowhead you can then make another one. Maybe randomly determine if the arrow is a complete loss, a partial loss (arrowhead goes in inventory), or no loss (you recover the whole arrow). I would assume in crafting you would have 3 components: arrowhead, shaft, feathers (fletching?). Then you put them together.