As aedan pointed out, the large border made the Anglo-German situation very tense.
As for the scenario where Russia doesn't move to Moscow (and let me say that moving A StP - Fin was very hard to refuse as an invitation for Russia to take back Moscow), it still would have been difficult for Russia to hold. They could build F Sev, as you suggested, but it wouldn't be able to make it in time to Anatolia to block us from moving two fleets into Con and Ank, and then it would be a matter of getting the army in Smyrna to Armenia or pushing BLA back (which is to say a 50/50 roll every turn to break the Russian defense).
As for the main front in Galicia and Romania, Russia could have supported you to Vienna with Gal instead of moving it to Rum (and A Sev would go to Rum instead of Moscow) but that would require trusting Austria to move out of Romania into Bulgaria, which would simply trade the gamble that we would leave Vienna to a gamble where we would leave Romania. It is understandable that Russia sought to avoid the risk and therefore risking your move on Vienna. HOWEVER, the Vienna fiasco could have been avoided if Germany supported A Tyr - Vie from Bohemia. With the army in Bud available to cut Tri, this move was 100% guaranteed. That was actually the deciding factor that allowed us to solve the conflict with Austria and eliminate them, rather than Russia's move to Moscow. With German armies in Vienna and Bohemia, Galicia (also known as the Gate to the East) was forfeit in your favor, and Munich could easily be kept safe with a modicum of forces (2 armies, basically, at least until I got to move an army to Bur), while Budapest and Romania would be under a lot of pressure.
So, yes, Germany did strategic mistakes in addition to tactical ones. If you sought to maintain Austria alive you would have one extra unit to stop my advance, and it could have been enough to stall me (at least until we broke through into BLA/Sev - but by then you could have reinforcements if you were successful against Britain).
Then in Winter you threw your hopes of victory out the window by disbanding both Silesia and Burgundy instead of offering the olive branch of disbanding Nth and save one of them from disband (probably Silesia to ensure you could secure Gal). Similarly, Britain not moving into MAO with support from Portugal also ensured we could stem any push they could make into the Med. Shame, I would have enjoyed facing an attempt at a Great Coalition and disappointingly none materialized.
As for the scenario where Russia doesn't move to Moscow (and let me say that moving A StP - Fin was very hard to refuse as an invitation for Russia to take back Moscow), it still would have been difficult for Russia to hold. They could build F Sev, as you suggested, but it wouldn't be able to make it in time to Anatolia to block us from moving two fleets into Con and Ank, and then it would be a matter of getting the army in Smyrna to Armenia or pushing BLA back (which is to say a 50/50 roll every turn to break the Russian defense).
As for the main front in Galicia and Romania, Russia could have supported you to Vienna with Gal instead of moving it to Rum (and A Sev would go to Rum instead of Moscow) but that would require trusting Austria to move out of Romania into Bulgaria, which would simply trade the gamble that we would leave Vienna to a gamble where we would leave Romania. It is understandable that Russia sought to avoid the risk and therefore risking your move on Vienna. HOWEVER, the Vienna fiasco could have been avoided if Germany supported A Tyr - Vie from Bohemia. With the army in Bud available to cut Tri, this move was 100% guaranteed. That was actually the deciding factor that allowed us to solve the conflict with Austria and eliminate them, rather than Russia's move to Moscow. With German armies in Vienna and Bohemia, Galicia (also known as the Gate to the East) was forfeit in your favor, and Munich could easily be kept safe with a modicum of forces (2 armies, basically, at least until I got to move an army to Bur), while Budapest and Romania would be under a lot of pressure.
So, yes, Germany did strategic mistakes in addition to tactical ones. If you sought to maintain Austria alive you would have one extra unit to stop my advance, and it could have been enough to stall me (at least until we broke through into BLA/Sev - but by then you could have reinforcements if you were successful against Britain).
Then in Winter you threw your hopes of victory out the window by disbanding both Silesia and Burgundy instead of offering the olive branch of disbanding Nth and save one of them from disband (probably Silesia to ensure you could secure Gal). Similarly, Britain not moving into MAO with support from Portugal also ensured we could stem any push they could make into the Med. Shame, I would have enjoyed facing an attempt at a Great Coalition and disappointingly none materialized.