Good job, folks. Melville kicked it.
1. A superhero. A supervillain. A covert political operative. A real-life movie star (made for TV movie).
Halle Berry in X-Men (and 2 and 3), Catwoman, Bulworth, and Introducing Dorothy Dandridge
Solved by Melville (comment #17).
2. A Quaker. The new husband of a Quaker. A fake suicide.
Gary Cooper in Friendly Persuasion, High Noon, and Meet John Doe
Solved by Melville (comment #1).
3. A princess. A beatnik-turned-model. A mother superior.
Audrey Hepburn in Roman Holiday, Funny Face, and Robin and Marian
Solved by Melville (comment #1).
4. A supervillain. A real-life singer. A cuckolded husband.
Kevin Spacey in Superman Returns, Beyond the Sea, and American Beauty
Solved by Trevor J. (comment #4).
5. A mother superior. The mother of a rabbi.A philandering music-hall performer.
Anne Bancroft in Agnes of God, Keeping the Faith, and To Be or Not to Be
Solved by Evn (comment #9).
6. A murderer on death row. A newly-inducted soldier about to ship out. A jazz guitarist.
Sean Penn in Dead Man Walking, Racing with the Moon, and Sweet and Low Down
Solved by Melville (comment #1).
7. The First Lady. A painter. A wealthy daughter planning her father’s party.
Marcia Gay Harden in American Dreamz, Pollock, and Meet Joe Black
Solved by Melville (comment #17). (But maurinsky knew it.)