Harry is disguised as Rons cousin Barry
If Barney is in the film - which doesn't look likely then his name has not yet been announced.
she is Bill and Fleurs daughter
If you are referring to Bill and Fleur's wedding, yes. Ginny and Harry's wedding, no. You see them with their kids.
Their wedding was not seen.
Gilderoy Lockhart in Harry Potter and the Chamber of Secrets.Hermione does in Harry Potter and the Deathly Hallowsas well. To the waitress and death eaters in the diner after they escape from the wedding.
Nobody died.
The death eaters crashed Bill and Fleur's wedding in the deathly hallows.
He is 16 at the very beginning, and he turns 17 before Bill and Fleur's wedding.
Voldemort's snake, Nagini, was not disguised as Bathilda Bagshot, but instead was residing in Bathilda's corpse for a short while.
He married Ginny Weasley. Nothing is known about the wedding.
It is the name that they gave Harry so that no one would know it was him at the wedding.
In Harry Potter and the order of the pheonix, she flirts with Harry but in the half-blood Prince, she is with Remus Lupin. They get married and have a child called Ted Lupin (Teddy) - named after tonks's father. He then is with Victoire Weasley (Bill and Fleurs Daughter) at Hogwarts - dont know where it goes from there.