Regarding lockpicking:
I feel a lot of games rely on a lockpicking system way too much as a way to put cheap hurdles in the player's way.
For PE, I would want it to be a restricted skill. Only characters with high DEX (or whatever stat is the closest to dexterity) should have access to it. In real life, if I'm not very good at doing precision work with my hands, I wouldn't be able to lockpick, period. I also feel that lockpicking skill progression should rely on experience as much as skill points. That is, you begin being only able to lockpick easy locks, and if you try a medium or difficult lock, you have a high chance of permanently locking yourself out of the chest (except if you find the key). You gain more and more experience, then you become able to lock medium locks quite safely. At the end, when you're very good at it, the chance of breaking a difficult lock could be reduced to 25%, so that there is always a risk.
Anyway, just some ideas.
Also, regarding mining:
I don't think it should be in the game, or if it is, it should be really carefully implanted. If my character is a warrior or a mage, he likely hasn't spent years in mines extracting minerals and ores, and that's what it takes to be able to mine something out of the ground. Plus, extracting is just the first step in the long chain that leads to having objects forged, so I feel like mining should be left to miners of the world of PE, not to adventurers who have so many other skills to hone. I don't think not having mining will restrict our experience of the game (but I guess that depends on the crafting system, in part).