Yes, when the first day of Succos comes out on Shabbos we mention Shabbos and say va’y’chulu and of Magen Avos. However, when the first day of Pesach falls on Shabbos we do not say of Magen Avos because the night of Pesach is considered a la’il shimurim, a night of watching, On Succos this reason does not apply. However, when we conclude the blessing of of Magen Avos we only mention Shabbos and not Succos, because the blessing of of Magen Avos was only introduced for Shabbos (Shulchan Aruch section 1, Aruch Hashulchan section 1, M.B. section 2).2. Are there any more changes in the Mariv prayers, when the first day of Succos comes falls on Shabbos?
When the first day of Succos comes out on Shabbos we are not accustomed to say the ma’arovis (various piyutim that are said during Mariv). Since people are not used to saying them, we are worried perhaps people will take candles in order to see them. On the second night of Yom Tov the custom is to say the ma’arovis of the first night that were omitted and not those written for the second night.3. Whe the first night of Succos comes out on Shabbos are there any additional changes during Mariv?
Likewise when the seventh day of Pesach comes out on Shabbos, on Mozoi Shabbos we say the ma’arovis of the seventh day of Pesach. Also, on Simchas Torah, outside of Eretz Yisroel we say the ma’arovis of Shmeni Atzeres, when the latter falls on Shabbos. However when the First day of Pesach comes out on Shabbos, on the second day we do say the ma’arovis of that day, because of the piyut "bcor lisfirah" (M.B. section 1, also see chapter 275 the Ramoh section 2).
Yes, we omit Bameh madlikin (M.B. section 1).Next Chapter