I would like to share my experiences and compare them with yours here. If it is indeed severely bugged I will compose a bugtracker report (not that there aren't tens of unresolved mining-related bugs dating several years there).
The issue is non-ore loot upon mining a node. From my observations with ~100 nodes its been ~350 ore, 12(!!!) stones and 1(!!!) gem. Didn't check prices on gems and stones on AH but it seems like they would be insanely inflated and leveling JC or BS would be a pain in the ***.
Does mining behave the same way with you? What do you think?
1 skill per node is Blizzlike, the first successful hit gave you skill and other successful hits after did not.
As far as the loot tables, yeah I think its bugged. I did not get that many stones when they are the most abundant things ever. Seems a lot of loot tables are messed up in vanilla zones.