*snip*
2. Sadly, yes. The problem is a lack of finer control over item types allowed. I can either specify a SPECIFIC desired item type (weapon, shield, body armor, legwear, tool, etc), or I can call for no item type and instead control the input via other means (reaction_class, hardcoded things like any_bone_material, etc). Doing the former leads to a lot of recipe bloat, while doing the latter leads to exploits. As it is, you can already use metal bars found in forts or other non-adventurer-crafted sources and they'll be good for 150 uses, as Adventurecraft recipes do some Fun things to work around problems with product_dimension not working right in adventure mode crafting.
When you said "150 uses" I had to check, and of course you were telling the truth that was not in doubt, but the bars I made from coins were only good for a single use. I'd say that's a kind of balance