The two main problems in this game, as I see it, are:
1. The scaling, or actually the lack thereof.
Affection and stars are on a scale, while the income is not, which will increase the gap between available income and funds needed to buy affection and stars. For stars 1 to 3 it is still doable, but stars 4 and 5 destroys the balance.
2. The waiting game!
This is actually the problem that makes people leave the game! When waiting for the next part of the quests, there is nothing to use energy on, which is a problem. Just logging in to battle a bit and collect cash from harem get boring really fast. Also, many contests needs us to use energy, which we can't!
So having something to use energy on while waiting is much needed. Preferably something that gives a bit of cash to help with the scaling problem and bring balance in things again.