Opinions are always most welcome, for sure. My response just tried to show the other side of the matter. Personally, I can bear quite a lot. But I've seen servers/admins taking the most liberal stace and dying quickly.
Also worth noting is the fact that I'm talking from demo servers admin point of view. You need to see that demo is for almost everyone the first experience with LFS and I really think being strict about language requirements there helps LFS as a whole, despite the fact that the filter fails in 1% or even 5% of cases. When I was new to LFS demo, I was racing only on AirAttack servers, because the admins were exremely nice and helpful, their language was polite and anyone swearing was kicked (using a very simple language filter in VCom).
Personally, I would not probably use language filter on S2 servers, because there are other means to fight bad language there.
Yes, in Airio versions up to 2.3.4 the Unicode character support is not universal and displaying extended characters on the servers page is not possible. Please update to version 2.3.5 (see my signature for direct link) which contains complete Unicode conversion support (unfortunately leading initially to some display troubles but hopefully solved now). I'm not sure if the Cyrilic characters would show OK in the console, but certainly server name should be OK then on servers page.