A very nice idea for a puzzle (again!), but once you're on the right trace and one's already solved the other pairings are not so tough anymore.
Just a similar case as it was in the 'art' group puzzle.
Sure. For a while I considered not answering at all to partially wrong replies (wrong man, wrong car or wrong event), and make it a little tougher, but my heart must be too soft.
I usually like to lead puzzlers away from the beaten tracks, towards films or anything. But here I think those three knew cinema well enough and needn't make too long researches.
I also took a chance by choosing some well-known actors, because I am often amazed how people won't recognize a face that's seems easy. Yet they recognized little known actors such as William Campbell almost as fast as Fred Astaire.