When Erev Pesach Occurs on Shabbat

I have some questions about when Erev Pesach occurs on Shabbat.

1. When is the Fast of the First-Born?
2. When Erev Pesach occurs on Shabbat when is Bedikat Chametz (checking for chametz)?
3. Do we eat bread at all of the Shabbat Meals?

First of all, a few relevant points of Jewish Law:

1. The Fast of the First Born is on Thursday. It begins at dawn and ends after the evening services. Preferably, one should not eat until after Bedikat Chametz, but may have a snack after the evening prayers if hungry. Many people attend a Siyum (a celebration of the completion of a Tractate of the Talmud), a Brit Mila, or a Pidyon Haben on the day of the fast, and are thereby permitted to eat afterwards.

2. Bedikat Chametz is done on Thursday night, immediately following the evening prayers. After checking for chametz, you should take any chametz that you plan to eat on Friday and Shabbat, and put it in a safe place where it won't be forgotten.

   One should burn the chametz on Friday morning, preferably during the fifth daylight hour (check a local Jewish calendar for the exact time). One does not nullify ownership of the chametz on Friday -- rather this should be done on Shabbat during the fifth daylight hour. On Shabbat one may not eat Matzah, because we want its taste to be fresh at the Seder -- so we must use bread for the Shabbat night and morning meals. Because bread may not be eaten after the end of the fourth daylight hour, one must eat the morning meal prior to this time.

3. The third meal poses a problem, because there are some Halachic authorities who state that the third meal must be eaten in the afternoon, and there are also authorities who rule that one must eat bread at the third meal. It is forbidden to eat bread after the end of the fourth daylight hour so what do we do? The preferred scenario is as follows: You get up very early on Shabbat morning, pray, make Kiddush, wash hands for bread, eat Challah with a light meal, and recite Birkat Hamazon. You then leave the table for a short while, wash again, eat bread, and again say Birkat Hamazon. All of this must be completed by the end of the fourth daylight hour. Later in the day you sit down to a meal of Kosher for Passover food (meat, fruit, salads). If the end of the fourth hour is approaching -- don't risk having another meal of chametz. Wait until later, and eat a meal that is Kosher for Passover.

4. Havdallah is said during Kiddush at the Seder.
   

Sources:

• Rabbi S. D. Eider - A Summary of the Halachos of Pesach.
• Yalkut Meam Loez, The Haggadah.
• Otzar Hatefilot, The Haggadah, Iyun Hatefilah.