I can see this from both sides. 99% of the time, the chopsticks question etc.. won't get to you. But sometimes people have bad days and it is those days I think where things like that, when they happen, will get to you. Personally for me, i find it enjoyable most of the time to shatter peoples stereotypes, and help educate a little bit. Usually i am in a good mood and more than willing to explain to people.. things like becki said that Asian cuisine etc.. is quite popular in Western countries therefore there are probably more Westerners out there who can use chopsticks than you think.

Also i think a lot of these stereotypes got their root when the world was less internationalized, like my father for example who is 64 would be a perfect stereotypical gaijin .. blond, blues eyes cant use chopsticks to save his life. From the younger Japanese population i tend to find these questions to be quite rare, and thus most of the time coming from people of older generations.

Chopsticks compliment: I actually don't hold them properly so, i explain that i hold my pencil weird too.

Language compliment: Hmm... well one time i remember i was drunk at conbini..... and these other drunk guys eyed me.. so i think i said konbanwa or something.. and they are like nihongo jyozu desune.. and i was like.. in a joking manner.. "oh come on..i say good evening and you compliment my "great" Japanese".. and we started BSing for like 5 minutes after that, it was fun.. but most of the time.. i just decline the compliment just like a Japanese person would.

They only thing that gets on my nerves regularly these days is being with my GF and getting ignored.. and it is not so much because i am getting ignored.. but the fact that my GF is 70% deaf, and cannot even respond half of the time cuz they do not look directly at her or talk with a "big mouth" so she can read their lips.. so i try to do the talking most of the time, and it can be a fight to get them to stop trying to ask her everything and address me.