Wine, matza, Shnakbone, egg, bitter herb, charoses (made from nuts, apple, wine etc.), green vegitable
Yes. Dog food is probably chametz on Passover and may not be owned by a Jew on Passover. Most dogs will happily eat Matzo and meat/chicken on Passover.
There are two options for Passover, you can cook food for your pets or you can purchase kosher for Passover pet food. Please see the related link for a list of approved pet foods.
Science Diet dog food does not have chumetz (leaven) in it, but it does have kitnyot (legumes). Since the food is created in a factory that is not supervised for Passover, you should buy the food before Passover so even if there is 1/60 chumetz, you are safe.
There is only one country which would consider Passover to be a national celebration, and that is Israel. However, there are many other countries in which Jews celebrate Passover.
Yes.
I'm sure they donate money and food.
Either the leaving of Egypt, or the slavery of Egypt.
The seder has evolved over time. Plus, sacrifice cannot be offered without the Temple so no sacrifices are involved in the Passover celebration.
No processed food is kosher for Passover unless its label has a symbol of reliable Rabbinic supervision.
Food is cooked no differently than at any time of year. We just use some different ingredients (only food that is kosher for Passover) and those who are observant will use different sets of pots and pans, dishes, etc.
It was the Feast of the Passover, a traditional gathering with food. Jesus used the symbolism as He became Our Passover - a blood sacrifice that could and does forgive sin and the guilt of it.
Kosher for Pesach (Passover) food is marked as such on the package label. Markings include a P incorporated into the hechsher, the words 'Kosher for Passover' in English, and 'Kasher l'Pesach' 'כשר לפסח' in Hebrew.