Michael Gambon
Ian Hart
He plays professor slughorn
Professor Gilderoy Lockhart
Professor Quirrel (Harry Potter 1). Also, his voice was used (modified) for Lord Voldemort.
Alan Rickman plays Severus Snape in the Harry Potter movies.
No, but you can get Harry Potter costumes.
Harry played, and won, against Slytherin and Hufflepuff in Harry Potter and the Philosopher's Stone. He missed the match against Ravenclaw as he was still in the hospital wing recovering from his battle with Professor Quirrell.
She was never in Harry Potter.
If you are talking about Daniel Radcliffe yes he did play harry potter in the deathly hallows... :)
There is no actor in Harry Potter of that name.
Yes, he does.
Professor Quirrel. He also voiced Voldemort in the first film because he was on the back of his characters head.