Truth is, physiologically women can orgasm as quickly as men, but they require a psychological component to make it happen. It's called romance. Bigger is better. BUT, the average vagina is three and a half inches long, and can expand with arousal and then contract, shrinking and locking around the penis. Unless you're exceptionally large or exceptionally small, a woman can't really tell how big you are.
Rapid ejaculation is caused by too much arousal.
No, it's caused by too much anxiety over coming too soon. Counting sheep or going over stock quotes in your head only compounds the problem by not allowing you to focus on the pleasure of the experience and most importantly, to relax. Only if you haven't had the really good ones as a basis for comparison. Both men and women have varying degrees of intensity and satisfaction from orgasm to orgasm. A vibrator in the sack is a sure sign of an unsatisfied lover.