I can't recall exactly when and why, but I recall an event where USA
imposed plenty of sanctions against Russia, but space station operations
were specifically exempted. At that time, USA still relied on Soyuz
ferry flights and progress resupply and reboost. (so after Shuttle
retirement, but seems older than 2014 when Russia took Crimea but I am
often wrong).

This time around, the USA is autonomous for taxi rides and resupply via
SpaceX. It has its own ECLSS, toilet and sleeping quarters as well.
But this time around, the sanctions are more severe.

Fair to assume that exemptions will be made to ensure space station
operations are not impacted?

Scott Manley explained that Cygnus is launched from a first stage built
in Ukraine and Russian engines. Assuming the Ukraining facility is
bombed tomorrow, would Northrop Grumman still make launches from parts
still in stock? Or are the rockets built "just in time" and one should
expect Cygnus to be grounded should the war last ?

Since this time around, there are also export sanctions by many
countries for various tech, could this impact Russia's ability to
build/luanch Soyuz?