You breathe a word of this, to anyone, you mincing fucking CUNT, and I will tear your fucking skin off, I will wear it to your mother's birthday party, and I will rub your nuts up and down her leg whilst whistling Bohemian fucking Rhapsody, right?!
Akira Kurosawa - cause I think he's the greatest director ever Steven Spielberg - cause he's not only one of the best directors ever, but his overall influence on movies and movie industry is enormous Clint Eastwood - cause he was equally great as director and actor, more than everybody else
Not really sure about the fourth. You could argue that it would have to be another director, cause it's just the most important facet about filmmaking. Alfred Hitchcock would be a good choice then, because he was so influential as well. You could argue for a woman among them, then I'd probably choose Meryl Streep. Or the greatest actor: which to me is Paul Newman. Or a screenwriter, but to me there isn't one that really stands out above all others.
I'll stick with dead American directors for simplicity's sake. It would feel weird picking living directors, even though many of the most influential filmmakers are still working. Robert Altman Orson Welles Buster Keaton Frank Capra
Alternates: Cecille B. DeMille John Cassavetes Sidney Lumet Billy Wilder Mike Nichols George Cukor