Devout Catholics tend to believe in the infallibility of the Pope. Papal infallibility in Church teaching is similar to a "Circular Reference" in a spreadsheet.
The first difference is probably that Roman Catholics are lead by and believe in the Divine authority of the Pope while Protestants do not accept the authority or infallibility of the Bishop of Rome.
i am orthodox and personally i have never heard of this papal infallibility been used in the church or dogmata.
Protestants are Christians.
Protestants WANT to be saved and know that if we believe in Jesus Christ, our souls WILL be saved and with him throughout infinity
Yes.
Protestants did indeed believe in good works. However, they did not believe one could earn forgiveness through good works alone.
No, Protestants do not believe in purgatory as part of their faith. Purgatory is a concept in Catholicism where souls are believed to undergo purification before entering heaven, but it is not a belief held by Protestants.
Of course!! The vast majority of Protestants accept the same Christian beliefs as laid down in the Creeds as Catholics believe. The only difference is that Protestants, on the whole, reject certain beliefs of the Catholic Church (such as purgatory, over adulation of the Virgin Mary, praying to saints, the adulation of relics, infallibility of the pope and so on) and regard them as unbiblical and an invention of humans rather than revealed by God, and they also reject papal authority in favour of the authority of scripture.
Yes
Yes, Protestants generally believe in the existence of guardian angels, who are believed to watch over and protect individuals.
Protestants are free to celebrate St. Valentine's day if they choose, but they do not believe "in" it, that is they do not rest any article of their faith "in" Valentine's Day.