Bag 14 (bag 7 for the station) went pleasantly well. Except for the explosion.
I assembled a window section and pressed too hard while snapping it into place. It took a lot of searching and cleaning to find the three missing pieces, but there was no permanent damage. After recharging the batteries (6 for the train and four for the remote control), the train ran like a champ. So I got courageous and ran it backwards for a while. There were no problems with the (unpowered) locomotive separating from the (powered) tender.