What about changing mining back to skill exp to level up, instead of skillpoints? Make it slow exp rate so that you have to work hard to be able to mine the best gems, instead of spending 500 points and being done with it? Would make players more inclined to mine instead of sacrificing 500 valuable skill points that would instead make you stronger.
The way mining is right now you cannot have a straight mining character. Perin and I have had a miner almost every version that we've played of quest except for the last few because it is basically impossible to do without leveling the character. That character was always our gold digger

This cannot be done anymore since skill points must be added. It forces you to have to lvl to be able to raise mining. I like simmias's idea of gaining exp for mining slowly. You can still keep the caps there for mining in certain area's (which others have suggest be changed) but if its done the way I am suggesting it will force people to mine to keep it near their lvl so they can mine where they fight. It would add another aspect to the characters I think and would be the only skill that you don't need to add skill point to if you dont want to. Hopefully that makes sense.