There was a similar discussion about death recently, you can read some of the replies for death in that thread.
Thanks for the link.
My personal favorites is what Servant said, or alternatively, having an inheritance system (most recently implemented in Rogue Legacy) - where your character really 'dies', but you continue to play with a descendant of your character.
The descendant system also gives opportunity to make death be an actual threat without having a total wipe. For example, one way to implement it is to have everything your character carries drop to the ground, while stuff in a bank or house storage or anything similar, stays the same. This way once you get some good minerals/ores from mining deep in a cave, you have to escape alive in order to bring them back, or you'll need to go retrieve them with your next character.
That's a rather good idea, which gave way to another idea I had. Depending on how a certain system comes to fruition in another part of the game, I could have an actual family system where at any one time, you can take a family member and be them (only the adults), and be able to specialize their skills somewhat. A party system, where you can actively control a single person, and if they die, it's permanent. Thoughts? Or do I need to be more clear?
As for mining, I've never been a fan of straight up nodes, nor am I a fan of regenerating ores. In your cave, you could have 'rocky' tiles that can be mined for a chance to obtain ores. Doesn't mean that each tile will yield an ore, while some may strike rich, and give you a few at the same time. And as you said, the deeper you go into a cave, the chance of getting better ores increases. If you can create fairly large caves, you'll never have to regenerate the ore randomly. To decrease travel time, you can add 'checkpoints' to the caves, so that once you reach a certain point, you can then go to and from the cave entrance straight to that point in the cave (sort of like "I've gotten here before, I'm know my character can make it there without trouble" thing). In a way simulating a mining tunnel system, since most serious mining in a realistic environment happens in deeper caves/holes.
I like the idea of not having actual ore nodes. And my main focus was getting rid of regenerating ores. So, essentially I can have all the rocks in the cave be a mining node, with a chance of getting an ore. Possibly a result of higher mining is the ability to prospect. Interesting...
My idea was to split the caves into "levels" where once you complete a level, you don't HAVE to go back through it. Essentially, you enter the cave, and walk through the exit of the first level into the second level. This now allows you to exit from the second level straight to the surface, or walk back through any levels you've already completed. I was thinking having each level be deeper and larger/more difficult.