Re: Station keeping
The Russian segment is designed to be run either automatically independently, under ground-control or via cosmonauts on board. The multiple redundancy was designed in on purpose. The Soviets & Russians have great experience with de-staffing and re-staffing space stations: e.g. Salyut (commonly unmanned), Mir. Mir did not suffer permanent issues with de-staffing. It did suffer from the collapse of the Russian economy after the break up of the Soviet Union meaning that the items that previously came from the Ukraine now cost a lot of money that Roscosmos (of the time) simply could not afford.