Love the mod so far. The only issue I found was that it's really is to "Bot". I got up to like level 18 in ten minutes and now I can mine rock in about three hits.
Yeah, I think that the EXP curve needs to be a bit steeper for levels above 5 or so, or I may start on the skills system which will allow different skills to be increased each level. The basis would be Mining, Carving, Prospecting and Gemcutting, which is the speed you dig, the speed you carve, your chance to get an ore chunk, and increased value of gems (respectively).
Mining and Carving are pretty obvious - each level is just one point of damage when mining
or carving.
Prospecting, each level is an additional 0.5% chance for an ore chunk.
Gemcutting, each level is an additional 2% value to
gems you process. Every other ore chunk is unaffected (Gold & Fool's Gold, Fool's Diamonds, etc), only Emeralds, Rubies, Sapphires, and Diamonds get this bonus.