I studid the link you provided. If those narrations are correct, then obviously the Bab isn’t the Mahdi of Islam for he failed to fulfill those prophecies. Furthermore, the narrations only stated that he will kill the enemies and I couldn’t find anything as radical as the Bab’s beliefs:
“The utterance of the [book or religion] of Bayan in the day of the appearance of his Highness A`la (meaning the Bab) was to behead, burn the books, destroy the monuments, and massacre [everyone] but those who believed [in the Bab’s religion] and verified it,” Abdu’l-Baha, Makatib, vol. 2, p. 266.