you define in treasure list
    material_quality 80
    material_range 9
this is nonsense ;-P
or better the millions of different throwing weapons and munition types is a mess and makes the item management for player and server unnecessarily complicated.

i remember you had anchored special material names, looks like you anchored this differents material names to  material_range?

I know you make trapdamage also to player items. if this damage hit's stacked materials, it's go to con of all stacked items?

clean your logic, make it simpler to handle and to understand.

1. throwing weapons or munition items vanish if you use it. i remember the days, when we collect our arrows and throwing weapons each time we used it.
2. if they vanish, they don't need that complexity of quality system.
3. "simplest logic" : if 100 arrows stacks and get a damage of 33, 33 arrows are gone.
4. "complexer logic": if 100 arrows stacks and get damage of 33, x arrows are gone equal to there material
i mean if the damage goes to wood arrows, more arrows broke, if it goes to steel arrows, lesser arrows broke.

i don't know, if you handle each unique item in a stack, when trap damage is inflicted or is the damage inflicted to the whole stack?

i would go first for a very low material_quality on throwing weapons and munition and destroy this kind of items with the stack count instead of the stack material

of course more enhanced is a handle each item in stack and pull it out of the stack with a unique con, but don't know if game needs this complecity for items vanishing when used.

i personaly would destroy x items in stack where x=inflicted damage/material_quality
and then wood arrows have material_quality 1 e.g.
this could be by done by material_qualtity or by material_range

so a self made wood arrow has
    material_quality 1
    material_range 0

or
    material_quality 0
    material_range 1

then it makes sense for a player to manage his arrows and try to get better arrows ...

but not that

    material_quality 80
    material_range 9

on all throwing weapons or munition

Overall, item quality/condition is a bit underutilized.

I agree that condition doesn't make too much sense on projectiles - the arrows still in your quiver likely won't be damaged, and if they are it'll be 1 or 2 vice all 1000. The reasoning is that it's the same code that processes q/c for all items. Should be simple enough to simply add an exception for arrows/etc. to either remove a few arrows or just ignore q/c.

As far as other items go, I think they should be spread out more so that upgrading from a pine bow to a birch bow is something players care about. Item quality/condition typically range from 80 to 87 (IIRC) which doesn't give a significant increase in damage unless you're upgrading from lowest quality to highest.

If we instead spread qua/con across, say, 50 to 80 with increments of 5, and reserve 81+ for rare artifacts it would be a more useful mechanic.

I'll try to work on this with the new server.