Michael Douglas!
Yes, you win. I <3 Michael Douglas, and have much more respect for actors who marry younger ladies than older ones(gross).
Like… cough Ahston K… cough
Clue 1: I’m one of the most promising filmmakers of this generation, and my first feature length production was filmed on black and white.
Christopher Nolan?
Yeah, not that difficult, coming from me His first feature length film, Following, was filmed in black and white.
You play now.
I’m an average actress who used to be married to an actor who is now with another actress.
Jennifer Aniston.
Ouch. You just kicked my butt.
Clue 1: I’m a short actress, famous for graduating at Harvard.
Catherine Oxenberg?
Nope.
Clue 1: I’m a short actress, famous for graduating at Harvard.
Clue 2: I’ve been in one of the most popular movie series ever.
Natalie Portman?
She went to Harvard and was in Star Wars.
Correct!
I am an inventor and founder of a company. I am British and most of my technology has to do with air/airflow.
Beats me. I don’t know anything about this subject.
From which era is him?
I am a racecar driver who always thanks his sponsors and says the right things.
Dale jr.? I am from this era and some of my most famous inventions suck
Close but not quite.
Uhm… Michael Schumacher?
If not for a few blimps in his career yes 
, but no.