Usually, I'd think added political correctness is silly and unnecessary. But how many of the non-hearing-impared would usually say, "let's go and pray with the hooknoses tonight!", or for dinner, "let's go eat at the slanty-eyes'"?

Yes, that bothers me too. But of course I can't put myself in the frame of mind of someone to whom those gestures are the habitual, normal words for the meanings in question. Does the nose-gesture in fact carry any sense of racial contempt to its users, or is it simply another arbitrary sign? The etymologies of many ethnic names are not very savory, if examined closely; but we don't examine them, do we?

This article is about British Sign Language, which is of course completely different from American Sign Language. ASL went through many similar PC changes at some point (maybe 10-15 years ago? maybe more?) and as far I know they were generally successful. (It's been many years since I studied ASL and worked at a deaf social services agency, so I am not an expert.)

The nose gesture probably doesn't seem offensive until you "stop and think about it", in the same way that sexist English words or things like the universal "he" didn't seem weird until you "stopped and thought about it" in the past.

Anyway I believe the change to more PC forms of ASL words came from within the deaf community, from the people who actually use the language as their native tongue. Although from the article it seems like the same thing has happened in the UK, just perhaps not as successfully.

An upright thumb wobbling from side to side?

Hmmm!! And what might THAT be referring to?

A wonderful social-studies teacher (polisci, anthropology, history, sociology, current events and a smattering of constitutional law) had her 7th graders for homework think of as many slang terms for different ethnic/racial/other groups as possible. The next day, in clas she split us into small groups to compile a list. Saying the words out loud, in the presence of other kids. Of different ethnic/racial/other categories. Eager young kids cheerfully collaborating, showing off, and suddenly hesitating - would it not be better not to know this word? Or that one?

Fascinating experience. I expect that British-Indians will be pleased. Gays perhaps less - having re-colonized the word "queer" I doubt they'd balk at a gesture...

What would be the difference between the gestures expressing such "neutral" notions (Jew, Homosexual, Indian, etc.) and the SL equivalent of racial or sexual slurs, if there is any? What is the way, in sign language, to distinguish concretely between, say, the objective "Chinese" and the offensive "Chink"?
Sorry if the question seems too naive, but I admit my almost complete ingorance of how sign languages concretely work.

I admit my almost complete ingorance.
IGNorance, ideed.

I am wondering how people from those particular groups refer to their own identities. And could Polari, for example, be spoken in sign language? I have also wondered how SL translates across other languages anyway.

I'm glad these changes are being made. It's a liberal wishywashyness, the worst kind of cultural relativism, if prejudice is not challenged across contexts.

Does anyone know why a sign "for 'Indian', which is a finger pointing to an imaginary spot in the middle of a forehead" is considered offensive, but a sign for "'Chinese' ... mimicking the tunic worn in China" isn't?

That's the thing—anything you pick out as characteristic of some group, and therefore suitable as a shorthand reference, can be taken as offensive stereotyping.