1)

(a)We just learned that, in Rebbi Yochanan's opinion, the Rabanan conceded to Raban Gamliel that the Shatz can be Motzi everyone with the Amidah. In that case - how can he issue a statement ruling like Raban Gamliel, which implies that the Rabanan argue?

(b)When Rebbi Aba returned from overseas, he reconciled the two statements - by establishing the former with regard to the Tefilah of Rosh Hashanah and Yom Kippur and the latter, with regard to the Tefilah of the whole year round.

2)

(a)In a third statement however - Rebbi Yochanan Tzipora'ah citing Rebbi Yochanan, rules like Raban Gamliel by the Tefilos of Rosh Hashanah and Yom Kippur (refuting Rebbi Aba's answer).

(b)Rav Nachman bar Yitzchak finally resolves Rebbi Yochanan's statements - by establishing the Rabanan who concede to Raban Gamliel as being Rebbi Meir, whereas the other Rabanan continue to argue with him.

(c)As far as the Shatz rendering Yotzei the community, the Amidah during the rest of the year is concerned - even Rebbi Meir continues to disagree with Raban Gamliel. Either way, Rebbi Yochanan rules that every person is obligated to Daven himself (like the Chachamim).

3)

(a)We initially think that the Berachos (i.e. the Amidah) of Rosh Hashanah and Yom Kippur are different because they contain many Pesukim - namely, those of the Musafin, as well as those of Malchuyos, Zichronos and Shofros.

(b)We reject that supposition however, on the basis of a statement by Rav Chananel Amar Rav - who says that as long as one says 'Na'aseh v'Nakriv Lefanecha k'Mitzvas Retzonecha, Kemo she'Kasavta Aleinu b'Sorasecha', it is no longer necessary to actually quote the Pesukim of Musaf.

(c)In fact, Rebbi Meir and Rebbi Yochanan differentiate between the Amidah of Rosh Hashanah and Yom Kippur and those of the rest of the year - is because it comprises nine long and intricate Berachos (as opposed to the rest of the year, when it comprises only seven). Note: This is not clear, since it is only the Musaf of Rosh Hashanah that comprises nine Berachos, not that of Shacharis and not that of Yom-Kippur (even at Musaf).

(d)Rav cannot have been referring to the Pesukim of Malchuyos, Zichronos and Shofros (as Rashi's Rebbes explain) - because we have already learned that one is obligated to cite at least three Pesukim according to Rebbi Yochanan ben Nuri and seven according to the Rabanan (See also Tosfos DH 'Ileima').

4)

(a)They thought that Rav Chananel Amar Rav's statement was confined to individuals, but that the Shatz must recite all the Pesukim. Rebbi Yehoshua ben Levi pointed out however - that there is no difference.

5)

(a)According to Rebbi Elazar, one is required to arrange one's Tefilah in advance (bearing in mind that the Sidur was not produced in those days). Rebbi Aba qualified Rebbi Elazar's statement however - restricting it the Amidos of Rosh Hashanah, Yom Kippur and Yom-Tov, with which most people are not so familiar; but with regard to the Amidos of the rest of the year, it is not necessary to do so.

(b)Rav Yehudah used to prepare even his regular Tefilah in advance - because he was so busy revising his learning, that he would only Daven once every thirty days (when he had finished his revision).

6)

(a)Rav Ada bar Avira citing Rebbi Shimon Chasida, rules that, according to Raban Gamliel, the Shatz renders Yotzei even the people in the fields, and certainly, those who are standing in Shul. This Kal va'Chomer is unacceptable however - because logically, we would say the reverse: Those who are in Shul should Daven themselves, seeing as they are able to do so, and it is only the people in the fields who need the Shatz to Daven for them, since they are unable to Daven themselves.

(b)Indeed, the Beraisa says with regard to Duchening - that the people who are standing behind the Kohanim during Duchening are not included in the blessing (because they should move and stand in front of them, seeing as they are able to do so), whereas the people who are in the fields are included, because they are unable to stand in front of the Kohanim.

(c)So what Rebbi Shimon Chasida really said - was that Raban Gamliel only exempted the people in the fields, who are not able to Daven because they are 'Anusim' (due to their work); whereas the people who are in town, and who are able to Daven themselves, are obligated to do so.