Well, 'A Christmas Carol' is primarily a story. It was written by Charles Dickens and has been adapted into plays many times, but the original form is a written narrative.
No. There is no information indicating that Melinda Dillon is involved in the new version of A Christmas Carol. The cast of A Christmas Carol usually consists of different actors, and it seems she is not part of this particular production.
The theme of generosity is very important in A Christmas Carol. At first, Scrooge is extremely stingy. But as he is visited by the ghosts, he realizes the importance of being generous. In the end, he becomes a much more giving person, giving money to the poor and being kind to those around him.
Yes. There is the original written version by Charles Dickens which has a very specific language and narrative style. Then there are film adaptations which often have to make changes for the visual medium. Some might cut certain parts, add new scenes for drama, or change the pacing, making them different versions in their own right.