even if you did change language in datatable... you`ll get errors and stuff because the original server language isn`t english and it`ll be pain in the arse to get dc/errors all the time. still.. if you want from the patch you add(russian) exclude datatable filed: NPC/langkor/any language named files/ and items....(that`s for English only!)
I warned you.. you`ll get a lot of dcs
PS: for the chat... you need russian language installed in your PC.. No other way ( try with russian client and after that find installer..)