I used to play on a Japanese server. Now I my main is on NA server, but I still have alts on my old Japanese server (Yojimbo).

There were quite a few people I knew, even on smol little Yojimbo, who were "foreigners" (feels weird calling them that since they were from a wide variety of countries), and most of them did not speak Japanese.

As the token Japanese speaking girl, they often asked me for help with stuff. :3

But as far as JP reception to foreigners who speak Japanese, I think that in general it is pretty good. I was part of a really welcoming FC and became really close friends with several people. They never doubted my Japanese skill or tried to "dumb things down" for me - they often just treated me as part of the gang, which I felt was really refreshing because I studied abroad in Japan and was not treated with the same amiability.

I think as long as you can make an effort to speak Japanese that people understand, say your よろしくお願いします and お疲れ様でした, and don't do the 迷惑, you'll be perceived and treated well, even as a foreigner.

Really, the only hard thing about playing on a small Japanese server for me was that when I was on all my FC mates were either at work or were sleeping. But, you get used to it and make time where you can.