I would probably send my atlantic sub after the Brit Med battleship - I would also bring along my battleship and transport. Load a tank on the transport and consolodate on Algeria. You might even land a fighter there on non-combat moves. You might also use one infantry unit to take Gibraltor instead of delivering a tank to Africa. This would prevent the British fighters from attacking your German med fleet in GB round 1.
I would send my German sub against the Atlantic fleet with 4 fighters and a bomber.
I would attack Karelia with all ground forces in Eastern Europe and Finland/Norway and with 2 troops brought via the german transport. Attack for one round only and withdraw to Eastern Europe. Hopefully you get more kills on him than he gets on you.
Think of it this way, if you loose less than 4, you come out ahead. You would have lost the 4 units in Finland/Norway one way or another. If you loose four units, make them all infantry - you saved the tank. If you loose more than four - you can shoot me. =)
Move southern europe infantry to western europe, land fighters there too. Move tanks in Western Europe to Eastern. Move German infantry to Eastern Europe.
The entire European allied fleet now consists of 2 transports and a sub in the med, and you’ve consolidated a large force in Eastern Europe.