A supplement to the Energy system
The Energy system is pretty neat, and I like it (as I've said before) but there's something I DON'T like about it. To get a lot of Energy and be able to play the game a lot per day, one has to spend a lot of money.
Now for casual players the Energy system isn't bad, but as is a player could easily spend several times the amount of money they'd normally spend on a subscription game over the same time period.
I wouldn't say I'm the best at economics, but surely there is a way to help long-time and loyal players save money on the game so they don't get agitated with the costs and leave.
My suggestion is to add a "Gold" membership that can be purchased for a one time fee (for a reasonable price for the game) that increases the recharge rate for Mist Energy by 100%, and provides special weekly or biweekly "Gold Member" discounts on Crystal Energy. This would reward players for continuing to play the game with special discounts while still earning the game and the developers a lot of money. It would also give the non-casual players more time per day simply by increasing the rate at which Energy recharges while still limiting them in their use of the Energy and not giving them any more of an advantage over casual players than they normally would just for playing the game more often than them.
It would also create four categories of players.
1. 100% Free players.
2. Game Purchasers who don't buy Crystal Energy.
3. Non-game Purchasers who buy Crystal Energy.
4. Game Purchasers who buy Crystal Energy.
Every person plays games differently, and my suggestion adds a lot more options for players to play, all depending on how much they're willing to pay.

honestly you havn't played the game enough then. its incredibly easy to play the game for hours on end without having to pay at all. you simply use the ingame market, and one dungeon run can easily generate enough crowns and more to sustain playing the game. i only see that you have to pay once anyway (when a player starts) just so you can get into the game. and once your at tier 2 the game is pretty easy to get enough heat crowns and whatever to keep playing. the only reason someone would pay more then once is if they blew there money on recipes that they didn't need or wasted money on unnecessary revives. and if there was this one time fee.....well the ce market would crash through the roof again, and the game would no longer become f2p

The exchange system could be easier to find. It's not obvious that you should go find and talk to the dude in red who will let you get CE for your crowns, especially if you've already found the always-visible buy CE with money button.

skaf, they changed that 50 patches ago.
The energy button takes you to the exchange now.
I'm not so sure on the specifics of your system, but I would definitely pay a one time fee, a pretty large one at that, if it allowed me to both play and craft in the same day without using micro-transactions, and to play without my friends and not having to worry about being left out if they decide to play later.