+1.. you can't choose seats when booking codeshare.. My suggestion is, once you get the record locator, go to USairways.com, manage your flights and choose your seats there (or give USairways a call, I have to do that for AA codeshare with Alaska metal).. As for itinerary change, my US metal flight (AA codeshare) was cancelled and AA gave me no notifications whatsoever.. Luckily, i was concerned and check USairways.com and find out before its too late.. So my suggestion for that is, go to US airways and double check.. I know its inconvenient, but they are just at the beginning of the merger, only 1 month in, cut AA a slack a lil.. Combining 2 different IT system can't be done overnight..