(1) The rule 14.7 did not specified the requirement of an unsupplied unit present when placing the Evacuation Marker. Does this mean it could be place alone in a Port hex to hold the port?
(2) Unit of different Nationalities could not voluntarily stack even with the Evacuation Marker in the hex, right?
(3) When the British Aid Marker advance to the "No Evacuation" Box, the Evacuation Marker is removed even if it is on the map, right?
(4) Dose the advance of the British Aid Marker due to rule 12.1, mandatory?
1) Yes it can be placed alone.
2) Yes units of different nationalities can stack with the evacuation marker. Read section 8.4.4, exception #2:
2) A mix of any unit nationalities can be stacked with the orange Evacuation marker or in Switzerland.
3) Yes, this is correct, read section 14.13.2, third bullet:
No Evacuation – Remove the Evacuation counter from the game.
4) Yes, it is mandatory.