I'm a behind the scenes person, very uncomfortable with attention. I would allow my discomfort to get in the way of performing.
However, I could see an INFP being a good actor if he/she was not shy and not inhibited, which many introverts are not. The character part might be easy, what with our complex imaginations. It's simply a matter of translating what is in your head to something physically apparent, but that's the case with all art forms.