Congratulations and hopefully smooth sailing from here on out.
That is very interesting about the text messages (not iMessages, right?)
Yes, these were SMS text messages held in queue.
iMessages have been working over Wifi all along. In fact, when I changed out the SIM card, I temporarily lost iMessage activation on the old phone number, but when I put the Sprint SIM card back in, the phone still programmed to the disconnected number and iMessage re-activated automatically too! Just another indication that this really was an activation issue after the port completed.