Some other suggestions on similar lines:
* Make it Easier to trade: As of now, the club members need to hop in each other's city to see what all items are on sale. How about, if a particular option on the list of the left is created, by the name of trade. And in that, all the items on sale, specifically in the club members cities' are visible.. If you wish, you can even allow purchase also to happen via that section only, and one won't have to visit the particular city to make the trade. I am imagining somthing similar to the Global HQ, but herein, only the items on sale, by the club members, will be available on display. All items infact, that would be better. Will make it much easier to trade amongst us.
* Option of taking a loan: At times, we are short on money and need instant money. How about we introduce an option to lend money amongst the club members.. and that can be paid back with an interest? Similarly, we can also have a lending system inside the city also.. Afterall, in real life too, many times, the governments take a lot of loan from various banks, which is repaid over a period of time.
* Option of making friends amongst club members, or strangers, who one visits via Global HQ: Currently, only Facebook friends can be made. But, why can't non-facebook mayors be friends with each other!? Like, there should be an option to send a friend request too over here. Also, as of now, suppose I really like a city of a particular mayor, whom I visit through the Global HQ, and I also like the items he has put on sale, but can only buy very few at the moment. Now, as per current scheme, there literally is no way out to reach out to that city again. Unless, by luck, it shows up in the Global HQ (Which is extremely extremely rare event). Hence, there should be an option to make friends between strangers, or newly found cities too.. That will lead to more game engagement, better options to trade also.