What about durability? Have you ever discussed about that?
Something like durability on tools, and pretty much whatever....
It could work, for example with tools, more you use your 40q axe more it will lose q, coming back to 10q....
This can open many different scenarios....like specialized resources: some wood and stones (same thing metals) will increase the tool durability, some others will increase the stamina reduction and so on..
Moreover it will boost the trade a bit.....somewhere in the world there could be the best carpenter ever, or etc....that sells his stuff, and you need to keep buying for the durability thing or bringing back your wepaons to sharpen(restore quality),etc... Sounds good to me....
Of course tools should last a reasonable time....not you have to make a new weapon every 5 minutes....
Let me know what you think about.