Why does one bless one's friend using God's name? Why are so many verses brought to prove this? Know the neesd of the generation and whether teachers are needed or not. That should determine whether one should learn or teach. The rabbis give meaning to the juxtaposition of nazir and sotah and also for gifts to the priest and sotah. A story was told about Rabbi Chanina that when he went to Babylonia to teach, he determined when the months would be. The rabbis in Israel were not please and sent messengers to threaten him. When the rabbis came to "the vineyard in Yavne" - the Sanhedrin - they began with drashot about the importance of learning Torah and of of the importance of hosting others.