By reading the scriptures I find the below answers to your questions:
1. What was the mission of
John the Baptist?
A. The Mission of John the Baptist (3:1–20)
Once again Luke sets his story in the context of world history (vv. 1-2). He then declares John to be the person expected to prepare the way for the Lord. With his concern for the church's universal mission, Luke extends the quotation fromIsaiah 40:3-5 as far as the statement that all humanity will see God's salvation(vv. 4-6).
At the heart of John's message was the call to a baptism of repentance for the forgiveness of sins (v. 3). This baptism symbolized both initiation and cleansing. It was used as a rite of initiation for gentile converts to Judaism, and the Jews practiced frequent ritual washings to cleanse themselves from defilement. The Baptist's claim that God could raise up from stones children to Abraham (v. 8) suggests that he regarded baptism as an initiation into a spiritual Israel. He also saw it as a symbol of cleansing from moral defilement. He put great emphasis on judgment and the need to bear fruit in conduct (vv. 7-9). He addressed social questions, including the sharing of clothes and food, honesty among tax collectors, and avoidance of injustice by soldiers (vv. 10-14). His denunciation of Herod Antipas for marrying his brother's wife and for other unnamed evil things was his most provocative ethical teaching. It was this denunciation that led to the Baptist's imprisonment and death (vv. 19-20; see Mt 14:1-12; Mk 6:14-29).
The Baptist prophesied the coming of one more powerful than himself who would baptize with the Holy Spirit and fire (vv. 16-17). This baptism took place at Pentecost and, of course, on subsequent occasions.
Spirit baptism may be accompanied by outward manifestations, but, being spiritual, it is essentially an inward change. It is described as a baptism with fire, says Clarke (1:53, on Mt 3:11), because the Spirit is “to illuminate andinvigorate the soul, penetrate every part, and assimilate the whole to the image of the God of glory.” The Spirit, says John Wesley (Notes, 24, on Mt 3:11), inflames people's hearts with the “fire of love.” The image of fire is often used for divine judgment. But insofar as judgment effects purification, it is not separate from baptism with the Spirit; it is part of the Spirit's work of inward change.
2. Why John The Baptist had to be born in a different way? To prepare the way of the Messiah, making his path straight. The voice of him that crieth in the wilderness, Prepare ye the way of the LORD, make straight in the desert a highway for our God. Isaiah 40:3
3. What did JESUS say about John?
I say to you, no one among those born of women is greater than John; yet the least ... that are born of women there is not a greater prophet than John the Baptist:
4. Do you think it was from God that Herod's daughter asked for the death of John and in this peculiar way? Yes I do think that it was in the plan of God for the end of John The Baptist ministry:
1At that time Herod the tetrarch heard of the fame of Jesus, 2And said unto his servants, This is John the Baptist; he is risen from the dead; and therefore mighty works do shew forth themselves in him.
3For Herod had laid hold on John, and bound him, and put him in prison for Herodias' sake, his brother Philip's wife. 4For John said unto him, It is not lawful for thee to have her. 5And when he would have put him to death, he feared the multitude, because they counted him as a prophet.
6But when Herod's birthday was kept, the daughter of Herodias danced before them, and pleased Herod. 7Whereupon he promised with an oath to give her whatsoever she would ask. 8And she, being before instructed of her mother, said, Give me here John Baptist's head in a charger. 9And the king was sorry: nevertheless for the oath's sake, and them which sat with him at meat, he commanded it to be given her. 10And he sent, and beheaded John in the prison. 11And his head was brought in a charger, and given to the damsel: and she brought it to her mother. 12And his disciples came, and took up the body, and buried it, and went and told Jesus. Matthew 14:1-12.
5. Do you think it was part of John's mission to die before JESUS CHRIST?
Yes I do think that God plan of John the Baptist mission was set to end before Jesus Christ. By reading the above full scriptures. Thanks. Now, what is your reason for asking?