In order to work for any Russian airline as a crewmember you have to be a citizen of the Russian Federation. Also proficiency in Russian is a must.
There are only a few businessjet pilots from the West - the owners get away with that somehow.
Maintenance and training standards are lower that in the US, but not by too much. There are nations in worse air safety situations.
PM me if you need more info.
Ex Tu-154 pilot.