Well, 'Hidalgo' has roots in true events, but it's not a strict, 100% accurate retelling. Some aspects have been fictionalized or enhanced to create a compelling film.
It's hard to say for sure. Some parts of the Hidalgo story might be based on real events or people, but it's likely that there's also a fair amount of fictionalization and embellishment.
Jaina Antonio was a character in the movie Fast Track, played by Claudia Giellini. She was the leader of the Camorra organization and the leader of the mafia. In the movie, her brother, Santino Antonio, planned to kill her to take her place at the high table. Jaina Antonio also appeared in the follow-up movie, The Fast Hunt 2, played by Claudia Gerini. Information about Jaina Antonio's character in other works or games was not available in this search.
We don't really know for sure without more context from the fanfiction itself. But they could be two friends, or perhaps they are characters from a particular series or universe that the fanfiction is based on.
The 2015 Ti champion was the Golden State Warriors. They won the championship in the 2014-15 NBA Finals with a score of 4:2 against the Philadelphia Cavaliers.