A) There is no such thing as "Unlocking" a CDMA HanRABet. Thats only for GSM HanRABets.
B) I'm not sure if MetroPCS will allow Foreign ESNs. If they don't then you are out of luck in this case. I haven't really looked at MetroPCS but you need to call and ask if they allow Foreign ESNs, As most carriers dont.
C) if they do than it will be debranded when you flash it.
Your better off asking in the MetroPCS forum, I'm not sure if anyone there really knows how to flash but we help people get there phone *ON* cricket. Not *OFF* cricket. so i won't be putting out any more information.