I presume the NS crew has gotten permission from the SWP Dispatcher for their operation on the SWP tracks, especially since they are occupying the Main Track and the Main Track beyond the clearance point of the switch to the 'Interchange' track. If the NS crew doesn't have permission of the SWP, that is a accident waiting to happen. The NS crew will also need to report CLEAR of SWP trackage.
100% correct. When we run over a foreign RR we call their yardmaster or in some areas go on their radio channel and talk to their crews.