Short answers, pulled from the story.
Saruman first appeared during a fourth phase of writing in a rough narrative outline dated August 1940. Christopher Tolkien has said that the creation process proceeded in waves, with the author rewriting the tale three times after producing the first half.
In the Mercian dialect of Old English used by Tolkien, the word saru means clever, skilful, or ingenious. This has associations with both technology and treachery fitting for the cunning man.
Christopher Lee portrayed Saruman significantly more active than in the corresponding books and appeared in several scenes not depicted in Tolkien's original work. Despite increased scenes in the first two films, footage shot for the third movie went unused in theatrical release.
BBC Radio produced the first adaptation of The Lord of the Rings in 1955 with Robert Farquharson playing Saruman. That recording has not survived but Tolkien was disappointed by it.
Treebeard describes Saruman as having a mind of metal and wheels while evil in The Lord of the Rings tends to be associated with machinery. Patrick Curry identifies Saruman as one of the key examples given in the book of the evil effects of industrialism.