Minor improvements
Just a few ideas here. I don't know if they have been discussed and are in the progress of being implemented already, but here goes:
1. Better overview of the cities.
The overview of the cities when pressing the 'cities' tab is good as it is, but could perhaps include building and troop training timers as well. That way, you won't have to enter each city to check if something is finished building.
This would reduce the amount of unnecessary server calls and the load of each. It would reduce the server traffic, if I'm not mistaken, and thus, ultimately, get more out of each server i.e. a cost-saving option, or in other terms, an profit increasing option.
(As some have mentioned, physical notifications would also be beneficial but this have been covered plenty before)
2. Trading of all chests, incl. silver and gold.
I believe it would be a mutually beneficial improvement for both developers and players if trading of the newly implemented silver and gold chests was made possible through the marketplace. Let me illustrate this:
I am currently sitting on a golden chest. Personally, I will never spend real money on virtual money (ie. coins) but rather enjoy the game as far as possible free of charge. This is unaffected by any changes whatsoever. I will therefore either sell my chest to an NPC, or I will wait, hoping that trading of these chests will be made possible and thus enjoy a greater trade value.
If the purpose of these chests was to increase the profits for the developers through this lottery which, what I assume, is based on an algorithm (and the likelihood of coins being spent on gambling is larger than on safe treasure purchases) ensuring that the aggregate outcome of these chests being implemented are increased coin spending within the game, then clearly enabling trading of this chests would further enhance this outcome.
As I am not willing to spend any coins opening this chest, I would be better off being able to sell it on the market than to an NPC (assuming there are people out there willing to spend the trade money and 10 coins to obtain whatever it yields) and since someone are willing to buy it, they must see this as a beneficial trade as well. What it would result in is a more efficient allocation of silver and golden chests, that is they would end up with those willing to open them, resulting in a larger (at least not a smaller) amount of them actually being opened, and more importantly for the developers, more coin spending.
3. Private Trading. (Just a brief discussion I though I might add)
This is also a well discussed topic, though I will spend some time on it anyway. I can see why transfers through the marketplace with its 10% commission fee helps to offset any effortless increases in money supply in the game (such as the daily gift, in contrast to hunting). Although regardless of this is the reason or not, it could be viewed as a matter of fairness.
Via the marketplace everyone has a chance to buy whatever is put out, however, this is not to say that there is an equal chance. Through coordinated marketplace trading within alliances, members of such enjoys inside information, so to speak, of when an item well below the market value will be place and therefore has a significant larger chance of acquiring said item. The implementation of private trading would therefore not, in my opinion, alter the current situation much. At least not to outweigh the enhanced enjoyment of playing the game this new feature would add.
As for the notion of fairness, it limits the public's access to some trading (some alliances not putting things out on the market to make sure that it does not fall in the hands of a rival alliance etc.) and might make the marketplace a second option for any buyer, with a decreased efficiency of trading in general. However, it would encourage people to treat each other nicer as all, then, are potential sellers.
I fail to see how this increased player interaction would outweigh the downsides of private trading, and even though as a player I would privately wish to see private trading implemented, it may not be the best option of the game. However, as stated before, including the enhanced enjoyment of playing the game with private trading, may all in all, increase player satisfaction thus increasing the amount of players and the length they play the game, leading to increased nominal amount of coin spending (ie profits for developers).
Like I said, it's just a few ideas to which I wanted to add my personal views as a player of the game. If any of it was helpful to the developers in their decisions regarding these topics, I won't charge a commission on the increased profits, but a minor recognition in the form of a few magically appearing coins on my account or an VIP status would not go by unappreciated, hehe!

Most of all, I just wish to see this game reach its full potential.
