The cast of Harry Potter and the Unlikely Collaboration - 2013 includes: Sam Cochrane as Ron Weasley Matt Gillow as Harry Potter Hannah Keegan as Hermione Granger
No, Alan Cumming has never appeared in a Harry Potter movie.
No. Copyright protects the Harry Potter name and the characters, and one would have to seek a licence to use them. Such a licence would be very expensive, and unlikely to be granted.
Charity Burbage is a character from the Harry Potter books. She was the Muggle Studies professor at Hogwarts and appeared in Harry Potter and the Prisoner of Azkaban and Harry Potter and the Deathly Hallows. She is executed by Voldemort after defending muggle-borns in the Daily Prophet.
The cast of Namaste - 2005 includes: Erin Borgfjord Wendy Deakins Evangeline Duy Lily Goncalves Marion Landry Koralee Nickarz Kate Potter as Narrator (2005-2006) Michelle Trantina
Well his character doesn't exist in the books so he isn't needed and it hasn't been announced that he is returning so it's unlikely.
Harry Potter and the Unlikely Collaboration - 2013 is rated/received certificates of: UK:12A
The cast of Potter Puppet Pals - 2003 includes: Neil Cicierega as Harry Potter
The cast of The Scaramouches - 1910 includes: Bertie Potter as Boy Gertie Potter as Girl
The cast of Our New Policeman - 1906 includes: Hetty Potter Gertie Potter
The cast of An Interview with Dennis Potter - 1994 includes: Judy Daish as herself Dennis Potter as himself
The cast of Rolf on Beatrix Potter - 2007 includes: Rolf Harris as himself
The cast of The Story of Peter and the Potter - 1953 includes: Allan Mills as Narrator
The cast of An American Potter - 1977 includes: Peter Sabin as himself Gerry Williams as himself
The cast of The Seekers Guide to Harry Potter - 2010 includes: Geo Athena Trevarthen
The cast of Harry Potter v. Voldemort - 2012 includes: Tiffany Berube as Carol
The cast of Be a Man - 2010 includes: Gareth Potter as Lewis
The cast of Potter of the Yard - 1952 includes: John Laurie as Edward Potter Hector Ross as Inspector Greenaway Avis Scott as Eloise Tremaine