Interesting. I would be nervous of writing in dS partly because of this whole problem. I'm from Sweden, and while I did live two years in the US when I was young, after that I've gotten most of my English from reading (I read a lot more than I watch TV). So I would be scared of writing dialogue, because I'm not good at slang expressions. I think it's significant that the one piece of fanfic I've ever written did not contain one line of dialogue. I could conceivably write Fraser, since he doesn't use much slang, but I couldn't write the Rays.

But, well, fandom is a lovely place even if you don't write yourself. : )