Can any amount of that Baltic Fleet survive exposed in SZ7 for 1 round to make it to the Med?
Absolutely. The subs can submerge. Although, they will likely be attacked by the US bomber on it’s way to the UK.
If the Brits bring only air and hit you 3 times in the 1st round, you might want to save the DD and take a potshot at one of the fighters because one sub is probably going to be killed by the US bomber. If the Brits hit 1 or less on the 1st round, you can also lose a sub and hope to hit with the DD or TP to force them to push a combat with bad odds or retreat and let the bulk of your Baltic navy make the channel dash safely. Submerged subs in sz7 also have an added benefit of scaring the allied fleets away from the Channel and mouth of the Med because on the off chance that the US bomber misses it can be really ugly for the allied fleets there. But you’ll have to position the bulk of your air forces in W Eur or north Africa to make the threat stick.
Can Germany hold against northern Allied landings that are basically unrestricted?
I believe you can. Your best bet for survival would probably be to try to drive a wedge in between the UK/US forces and the Russians to prevent them from massing in one territory. The longer you can keep the UK/US bottled up in the north the less Russian reinforcements you’ll see because Japan will start demanding more and more of Russia’s attention.
Can the Axis take enough of UK’s income fast enough (the 18 IPC’s from Africa and around the Indian Ocean) to prevent UK from totally dominating northern Europe?
That’s a hard question to answer.
The UK never really dominates in Europe. They need allied help. If Russia is pushed far enough, the UK is little more than a nuisance to Germany even if they are landing max ground units. But it becomes more significant if the US is also landing units and the total force becomes 12+ units per turn. Which brings me to the real reason for the threat of mass African landings by Germany.
Diversion. Specifically aimed at the US. Landing in Africa either forces the US to divert their forces to Africa or let Germany get a whole bunch of free money for little effort. The Axis should always be looking for their units to be doing something not being idle. They should either be killing something or moving someplace to kill something. if you let the allies bog you down into a war of attrition you will lose. Africa provides you with the ability to kill things and move to kill things. The TP’s also serve a dual purpose in that respect. You can not only cork up Egypt and pinball a couple armor down south to grab the money but with the second TP you can also threaten a whole bunch of territories with a good amount of force or just bring the African units home to provide extra punch in Europe if needed.
Don’t get me wrong, the money is important, but what’s more important in Africa is isolating the allies, specifically the US, in their own little theaters where you can destroy them individually as opposed to trying to crash through a combined allied wall.
With UK reinforcement free from the north, can Germany/Japan succeed in taking Russia via Caucuses route?
The north is NEVER free from UK reinforcement. There is rarely a time when the UK will have an empty transport, even with Africa lost, it just depends on whether there are armor being TP’d or just all inf.
Germany’s role in the Caucasus route will most likely be to trade Russian reinforcements to allow Japan to make some headway in Asia. But don’t forget the Afrika corps. If the heat gets too much from the US you don’t have to TP them back to Europe. You can always walk them to Persia. By then Japan will probably own it and those German reinforcements can really put the screws to Russia in Caucasus.
Hope that helped.