The Jewish Calendar was lunar, and implemented “leap months” (adding whole months to certain years) to stay roughly in sync with the solar cycles. As a result, the date of Passover, 15th day of Nisan, shifts back and forth on the solar cycle (Julian/Gregorian calendars).
Basically, if you look at the jewish calendar, it is possible for the same day to occur twice within the same solar year. Pagan Rome took offense to this idea, and made the solar calendar the standard for the empire. As a result, the Christians converted to the solar calendar outright, and created rules for when the Christian Passover would occur which would always place our Passover close to the original Jewish Passover (15 Nisan).

You are missing something if you think the entire world of Chrisendom calls Easter by the word “Easter”. MOST of the Catholic church calls it Passover, and it is only in English Speaking countries that we refer to it as Easter. This is because the word easter comes from the old english word for Spring (Eostre).
Latin: Pascha
French: Paques
Italian: La Pasqua
Spain: Pascua
No. Not in the holiday itself. There is the controversial claim that the word Eostre comes from the germanic goddess’ Ostara’s name… but the evidence that there even was such a goddess or that she was worshipped is highly suspect. In fact, the ONLY source that claims that Ostara was a goddess who was worshipped was the historical writings of the Venerable Bede… who was writing hundreds of years after the death of the tribe he was referring to and made no mention of how he arrived at the idea that such tribe had a goddess named Ostara. Many recognize that Bede was probably wrong, and that ostara is simply a formerly used word for spring.
Others claim that the word Easter comes from Ishtar, an egyptian goddess. However, that would only make sense if the word Easter had NOT originated in old English rather than in Latin. There is no evidence that the English pagan tribes EVER had any communication with Egyptians or worshipped the same gods and goddesses. There are literally tens of thousands of presumed pagan deities because of the localization of pagan faiths.
That being said, while the holiday itself DOESN"T have pagan roots, some of the secular traditions practiced in English speaking countries (such as the bunny and the eggs) probably do. Do note: bunny and eggs are NOT universal traditions of the church.