Regarding Ethnicity

That's not nearly as hard as you might think. For the most part, the inside of a black character's mind is going to be the same as a white's. Depending on background, the differences are going to range from purely superficial, to differences in cultural values and worldview. But they're not aliens.

I think njrick and SNM have made good points here. As it happens, I'm white but have plenty of experience of Black (African/Caribbean) and Asian (Indian subcontinent) people, so writing about them is no more challenging than writing about someone who's a banker, farmer, conservative or expert chess player (none of these applying to me). Some of the shades of culture are helpful to a spanking story - for example, on the whole an assertive young ethnic Indian or Pakistani woman has had to strive a bit harder to be accepted as an authoritative professional or someone who can openly disagree with an older male than would be the case with a white or Black Caribbean woman, for cultural reasons but also because of stereotyping by other groups. That can be interesting in a spanking context.

Actually, in humorous stories stereotypes can be useful, especially if you go along with them and then suddenly depart from them. Finally, SNM is right and there is no need to worry that, for example, a Black merchant banker character is incredible just because there are few Black merchant bankers, any more than you should hesitate to introduce a teetotal Glaswegian (often stereotypes have a smidgeon of truth). "You are all individuals. You make your own decisions!"/ "I don't!"

That I know. Which is why, for many characters, I don't try to decide on, or describe, any ethnicity. To decide to make a character, say, african-american, is to decide that that's important, and therefore seems to require a point of view that comes from a particular cultural perspective. Generally, I leave out those details because they are unimportant in my story; I'll let central casting decide who can best play the part.

I number amongst my professional colleagues a goodly number of extremely clever, high-achieving , and authoritative Asian women.
In my experience none of them have the slightest difficulty in openly disagreeing with males, or forcefully expressing their opinions.
Where they do unfortunately have problems is in finding a husband, as many first-generation parents and their sons still want a conformist and submissive wife.

Made more difficult, of course, by their desire to conform with expectations enough to want to marry within the ethnic group (by my observation).

I live in a largely Anglo Saxon community, so that's just how I tend to portray my characters, although I have also done Asians, Mediterraneans and Latinos.

Both true. I sense that for many feisty young Indian subcontinent women, whether they have indulgent or traditional parents - and both occur, though the traditional (at least for ethnic Pakistanis) are probably rather more common than among white Anglo-saxons - they have to cope with attitudes around male and older people dominance somewhere within their community, often family, and this gives hones their assertiveness (wow, that became ass sertiveness, can't think why) much as growing up in a tough neighbourhood can help some boxers, police officers etc. An ethnic Indian acquaintance who held a lowly position in a hospital expressed something like despair that when he met female Indian doctors in the corridors, they cast their eyes down before him and walked by like demure inferiors. Now it's entirely possible they wouldn't have done that if he'd been white or black.

I think its called a Freudian slip, LOL, I make a few of those myself

I've never written any spanking stories about other races. I do have an idea for a spanking story involving a race of aliens with blue skin that I may write someday. the topic reminded me of a RL situation. I grew up perhaps a quarter of a mile from a retired school teacher. She was a good friend of my aunt and related some of her teaching experiences involving corporal punishment to her. My aunt would then pass these stories on to me. Schools in my state were only integrated toward the end of my neighbor's career. Once she began to teach black students, she tended to spank them for things which she would let a white child off with a warning, or perhaps make the white kid stay in during recess.

Blue skin probably means that they have copper-based blood. If this is the case, their bottoms would turn green when they get spanked, as that's what happens when cupric blood is oxygenated (lobster blood turns green when it comes in contact with oxygen, for this reason).