@masaykh: "cyrillic letter Я in mainmenu showed like this :" ->> Sorry but you have to be more specific. I'm unable to locate where the wrong "Я" could be as I don't speak a word of Russian
I guess this is due to the fact the Russian patch modify the Windows font used in game. Try to replace with the default font here https://dl.dropboxusercontent.com/u/369241/sylfaen.zip, copy it into C:/Windows/Fonts/, restart your computer and tell me if it worked.
1 - Thank you for reporting this! I totally forgot about that point! I'm afraid I won't be able to improve this as it cannot be rendered like any other texts but I can try to disable the feature on non-default languages.
2 - This is probably a translation error. Several Russian strings have this error (even in the launcher). Why does Russian have so much differents forms ?
EDIT: Thank you for the MinGW trick. I'll try that!
@instans: Thank you also for the report. I'll see what I can do to improve the city and sign text. Note that you shouldn't use a C-RUS or 1C-RUS version with our mod. It is designed to work on the Euro/US version (but there are still bugs like this).

1 - Thank you for reporting this! I totally forgot about that point! I'm afraid I won't be able to improve this as it cannot be rendered like any other texts but I can try to disable the feature on non-default languages.
2 - This is probably a translation error. Several Russian strings have this error (even in the launcher). Why does Russian have so much differents forms ?
EDIT: Thank you for the MinGW trick. I'll try that!
@instans: Thank you also for the report. I'll see what I can do to improve the city and sign text. Note that you shouldn't use a C-RUS or 1C-RUS version with our mod. It is designed to work on the Euro/US version (but there are still bugs like this).