The US has captured Norway, and then the next turn placed a factory. Is it legal for the US to deploy ships into seazone 113, which is inside of the Danish straight? Clearly they could not pass through without holding Denmark itself, but it seems to me that there is no reason that the US could not deploy to that zone for additional pressure on Germany!
You are correct. Since the ship is being built it does not have to pass through any strait. A minor factory in Norway may build up to 3 ships per Turn in either SZ126, SZ125, SZ112 or SZ113 or any combination thereof.