I've had sex with about 30 or so Asian women who were either Thai, Korean or Chinese. Clits like cocks vary in size, but the Asian women I've had sex with generally had smaller clits, and at their biggest were about average for a white woman. It is no obstacle to sex, other than you need to tease it out a bit to stimulate it. Other than that, I quite like a petite clit that hides until you decide to play, it's very discreet and delicate.
Having had sex with so many Asian women, there is no doubt they generally have short, tight vaginas. At biggest they are average in size, but about 2/3 were tight to very tight for me. One girl was too tight to be comfortable with me and we had to break off our relationship, and a few others were so tight I could have come on three or four thrusts if I didn't know Tantric sex and worked really hard at prolonging myself. They were t-i-g-h-t, tighter than anal sex.
My wife is African and she has a very large clit, but being the only African I've had sex with I don't know if this is a common trait or not.
I've never noticed the vagina location thing with Asian girls but I've read of it, and I am guessing that if there is a difference then it's probably a small one. My African wife's vagina is certainly located more rearwards, but given my size that's probably a good thing.
Symphonic: where did you get your research from? I would love to know, because my anecdotal experience is not one or two but many, and I am convinced there is an average size difference. Has there ever been a study on clitoral size? If so, I haven't read it.