Rabban was a title reserved for the leading Rabbinic authority, known as the "Nassi" during the early "Tannaic" period. Tannaim were the rabbis who compiled the Mishnah, which forms the basis for the Talmud.
Hillel, Rabban Yochanan ben Zakkai and Rabbi Akiva all lived to 120.
Rabban (Rabbi) Yochanan Ben Zakkai (1st century CE) was one of the foremost students of Hillel. He was the teacher of Rabbi Eliezer and Rabbi Yehoshua, two of the greatest sages of the Mishna (transmitters of the Oral Torah traditions). Rabban Yochanan ben Zakkai is mentioned, among other places, in the second chapter of Pirkei Avos. As related in the Talmud (Gittin, folio page 56), it was thanks to his interceding that the Roman leader Vespasian allowed some of the Torah-sages to survive the Second Destruction when the Romans destroyed the Temple.
Rabban (Rabbi) Yochanan ben Zakkai (1st century CE) lived his entire life in the Holy Land, in Jerusalem, and later in a town called B'ror Chail (in his last years). His chief disciples were Rabbi Eliezer and Rabbi Yehoshua, the teachers of Rabbi Akiva. Rabbi Eliezer settled in Lod, while Rabbi Yehoshua lived in Pekiin. Rabbi Yochanan ben Zakkai was also famous for creating the Yeshivah at Yavneh (Talmud, Gittin 56b).
Rabban (Rabbi) Gamaliel was a leading sage and member of the Sanhedrin (Jewish court) around the year 100 CE. His name is found many times in the Talmud and Mishna.
The Ashkenazic Jews, call him a Rabbi or Rebbe. While the Sephardic jews call him a Chacham (lit. a wise person). Rabbi and Chacham are their titles as well.
No.
It would depend on the Rabbi... but I have been to many weddings between Jew and Gentile, some were officiated by a Rabbi and some jointly with a priest and rabbi.
The Torah-learning was at a level of extremely high activity. Sages such as Hillel, Shammai, Rabban Yochanan and hundreds of others, each had hundreds and sometimes thousands of disciples. Rabbi Akiva began his career during this century and had 24 thousand pupils before the close of the century. Rabban Yochanan had so many disciples that they had to learn outdoors since no building was big enough. There were some antagonistic groups, but they were minorities and had no influence on the vast majority, who sympathized with the Torah sages.
There is no direct relationship between lettuce and a rabbi, as lettuce is a vegetable and a rabbi is a religious leader. However, both are part of the world, and a rabbi may offer blessings for the growth and consumption of lettuce as part of Jewish agricultural customs.
(Talmud, Gittin 56a) Rabbi Yohanan ben Zakkai didn't approve of the Zealots' plan to wage war with the Romans. The Zealots tried to force the hand of the Jerusalemites by burning the city's stockpiles of food (ibid.); and Rabban Yochanan feared that thousands would die in the famine which the city was plunged into. He decided to try to go and plead with the Romans to lift the siege; but the Zealots weren't letting anyone leave the city. For these reasons, Rabban Yohanan had to be smuggled out. He feigned death and was carried out in casket (ibid).
Originally, it was a rabbi, a rabbi, and a rabbi walk into a bar. . .
Rabbis. Here are a few examples from the Talmud. Rabbi Yochanan ben Zakkai, Rabbi Yonatan ben Uziel, Chanina ben Dosa, Bava ben Buta, Shimon ben Hillel, Rabbi Eliezer, Rabbi Yehoshua, Rabbi Yossi haKohen, Rabbi Shimon ben Netanel, Rabbi Elazar ben Arakh, Rabbi Yochanan ben Nuri, Rabbi Akiva, Rabbi Nechuniah, Rabbi Nachum Gamzu, Rabbi Yossi Glili, Rabbi Honi Me'agel, Rabbi Abba Shaul, and hundreds of others. Each of these had large groups of disciples.