You probably shouldn't answer questions that you don't know that answer to. Yes, you can get both nobility and health crystals after full mastery. Nobs are usually 1 in every 100 (for me), and crystals (for me) have been 1 in every 10k. I'm approaching 30k total quests done across resets and and accounts, and have only gotten 3.
People would complain that "the rich get stronger as the weak get weaker" and "it's no fair for the smaller players" etc etc.
You get a small boost in stats at the risk of resetting back to base stats(some pieces can't be reset). ★Equipment Enchantment Guide★ By the way, I apologize it's not completely finished. I have been slacking.