I have just two suggestions that I can think of that I think would be a great addition to the game.
Invisibility spell:The archer queen's ability makes her invisible for a short period of time. I think if this was added to the game for roughly around the same time as the first level that is correlated with the AQ's ability at level one would be suffice. Along with the creation of this spell; it should take up 2 spell slots compared to just the one like rage, heal, jump, and freeze. It should be added after the freeze spell and the slots for the spells should be kept at the same. It should be kept the same because if someone wanted to, they could easily load up on the freeze/rage spell and just steamroll someone.
Collect all option:This one I believe would be extremely important. I play on average 6 hours a day on this game and it almost never happens that I manage to collect from every single collector/drill/mine. There should be an option either on the Town Hall that you can collect from all collectors.
Let me know what you think about these two suggestions!!