Just a quick heads up:
I had a lot to do during the last day. But the update is ready and will be going live tomorrow - just in time for the big competitions!
It will include a few of the mentioned ideas - like a Quest System and new means to get monsters.
I find the idea of increasing the maximum amount of energy very interesting, I am sure to find a good solution on this soon. In the upcoming update there will sadly be no marketplace included - I am still struggeling to find a solution on ensuring you cannot do any fraud with it (for example by multiple accounts).