1) Valestone and moonstone are prolly reserved for 2 extra sprites... If not though, i would rather make it possible to use both as a food too.
Pretty simple concept...By mixing Valestone and Moonstone you create Appetite pills. Feed it to your sprite to make it hungry again.
2) Cheaper energy will kinda solve this problem. Market is very harsh now to newer players. Hell, I have all 5* gear one might need...But i still find it too hard to get CE with current cost.
3) With that "algorithm" depot costs can be lowered to 1CE for everything.
You simply stack up some CE, then guys-who-control-market-prices rise CE cost to 999999999 aaaand boom! Depot prices drop, but everyone already have CE to spend.
1 - We have a thing called Unique Variants. We dont need weapons getting more powerful. But we still haven't decided a use for Moonstone and Valestone. If you want to deal with your useless minerals, then you can make Sprite food and trade them or something.
2 - I'm not sure how to help you with that. Check the Orb rates on the wiki for a good orb farming mission.
3 - I'm not an economical pro, but that just sounds bad.