Yes, you have to be Jewish to become a Rabbi.
No
no
It is because rabbi is a respectful name meaning teacher.
You would have to ask a rabbi this question; but generally, a rabbi preaches about the Old Testament and the Jew's religion, and as such they cannot believe in Jesus, as the Apostle John says when he talks about them in John 12.39 & 40
They called him rabbi, or teacher.
Lord, Master, Rabbi
This is another name for Jesus.
Unless the rabbi was a Messianic Jew he would disagree. A Catholic priest would agree with the claim that Jesus was God.
Jesus was likely a member of the Jewish sect the Essennes (many of his teachings parallel theirs), and he was a rabbi. To be a rabbi back then, the process is somewhat different than now, but generally one is required to go through a rigorous training process, and one spends a long time as a disciple to other rabbis before they can become a rabbi themselves. It's a matter of training time. Jesus likely spent most of the thirty years as a disciple in training.
A guy, a rabbi, and Jesus walk into a bar. The bartender looks up and says,"Don't tell me this is some kinda stupid joke"
Rabbi