Well, there are alot of good points throughout the various posts, these are my 2 cents :
1. instead of making alot of different metal ores, in my opinion (and as it was suggested in the original thread post) there would rather various ores,minerals and such - so you mine a certain number of metals, yet you can mine minerals such as sulphur (used to heat forges every hour or so, to heat ovens and etc), coal and other minerals, various types of gems, etc ...
2. when planning the mining procedure, care should be given to beginner and veteran miners, i just think a low level miner who mine simple materials shouldn\'t worry about too much, and a veteran miner who mine high-grade materials should worry about dangers (monsters, etc), and depth (rarer materials go way deeper into the mines) which means plans of how to carry it to the mine enterance.
3. to give a skill depth (or should we say prevent it from being so dull as a click and get), you don\'t have to have grand things like cave-ins, or frames - as much as they are realistic and of course really cool, they are demanding when it comes to computer power and design/programming time.
Just in the same way a \"bad\" game will have a smith turn materials into a sword, and a \"good\" game will have him spend a little more time in the various stages of making (blade heating, hammering etc),
a miner can and should, in my opinion, have some stages of his own, if you think a smith does the smelting than i have to break it, it\'s terribly wrong - smithes never had and never should work with non processed ores (not to mention how heavy it is) - and since there obviously shouldn\'t be a special skill to it, i think a miner should take care of the smelting, which enriches this skill quite a bit.
* most of the mined ore is dirt, so the miner gets rid of a lot of it in the smelting process, plus he needs to heat every once in a while the smelting oven/forge, to turn the processed ore into metal ignots. (based on coal/sulphur or so)
* as it has been mentioned well in a couple of previous posts, a lot of finished materials are made of a few different kinds of ore, so to make say mythril, you need to smelt processed silver and iron together, etc ...
this somehow brings sanity if there are a lot kinds of different minable ores.
4. about the guild thing, i\'ve been thinking pretty much the same, mining guilds (or companies as it has been in our past) ussually had mines filled with carts and support wooden frames, and smelters equipment near the mine enterance, those are various things which are made to speed \"group\" mining.
I think this is a good idea, and it can introduce a really good workflow, as roles can be devided in order to have a bulk production rate which gives your guild a good reputation as a supplier (a good way to ease the time it takes to sell the fruits of production).
But it seems guild was reffered to a clan at some posts, and to a guild in others.
I think having a clan owning a mine or so is very terrible, as for guilds i think it\'s great since guilds are the signs of a living economy, (guild is a hierarchal group of people sharing the same job) in my humble opinion seeying self-efficient people who sell their products-completly-made-from-scratch-alone is simply childish, stupid and unrealistic at all.
