Raboh said Y.H.N.K, and Levi said K.N.Y.H. - רבה אמר יהנ"ק ולוי אמר קני"ה
Summary:
The רשב"ם is גורס לוי before רבה, since לוי was a colleague of רב ושמואל, while תוספות maintains that the order here follows their preference for what comes first; יין, קידוש, or נר.
Summary:
We place the הגפן adjacent to הבדלה, since only הבדלה requires wine (רשב"ם), or because people may mistakenly assume that the הגפן is only for קידוש.
And Rabi Yochonon said the people conduct themselves like Bais Hillel - ואמר רבי יוחנן נהגו העם כבית הלל
Summary:
ר' יוחנן learnt that the משנה of ב"ש is not a סתם but rather the view of ר"מ (and ר' יהודה disagrees). The נהגו here means that it is a proper custom.
You did not know whether they will give you to drink - לא הוי ידעיתו אי משקו
Summary:
They either made a ברכה over each כוס by the ריש גלותא during the meal (רשב"ם), or (תוספות) they only made a second ברכה over the כוס ברהמ"ז, since they were unsure if they will partake of it.
I was acting like the students of Rav - אנא דעבדי כתלמידי דרב
Summary:
רש"י maintains that wine which is drunk during the meal requires a ברכה before and after (even if reciting ברהמ"ז). תוספות and the רשב"ם maintain that no ברכה אחרונה is required, for they are exempt by ברהמ"ז. Nowadays there is no concept of לאחר הסעודה, since we are not מסיח דעת from eating until ברהמ"ז.