How appropriate. You fight like a cow.
Easy, you may muster ships in any adjacent sea area (not just the area the port is facing), as long as no enemy ships are present there.
In effect, a ship mustered in Winterfell may be placed in 3 different sea areas or the Winterfell port.
Hope this helps.
Hmm, I only see two sea areas plus the port (Bay of Ice and the Shivering Sea).