After LocalTrader, our next big project will be HD wallets, so all of these issues will be taken care of automatically, with new change addresses generated every time.
Please consider leaving an option for the user to select his own change address. I like to generate my own private keys offline and track them on multiple apps.
HD Wallets are fine but I'm hoping not to be locked-in to using HD generated addresses exclusively.
we are not 100% sure how HD will be implemented, but the general idea is that it should become easier, for the user, as much as possible. is there a good reason for manually specifying a change address?