Only a Russian keyboard or a plain US keyboard as long as you can manage without labeled keys (or maybe obtain the labels): just enable the keyboard layout in your operating system. Most system fonts already have Cyrillic characters. There is a setting to index and sort field data using Russian locale, but even with English index and sort it still works pretty good. I'm not sure if you need typical Russian date and number settings; probably not.
To do a full Country default, you should set that Country as you System defaults BEFORE creating your FMP database. FMP stays with the Creation Country as a default and you must handle the 3 items as needed for alternate countries.