Thank you for quick and clear answer (as you always do) and thanks Geist for helping.
Question about the Baltic
Is it necessary for axis or allies to control Norway and Denmark at the start of their turn, in order to enter/exit the Baltic Sea with non-subs?
If this is not the case (particularly, if control of Denmark alone is necessary), is this a rule Larry has changed recently?
You only have to have control of Denmark, and that is for all Naval vessels. There are no exceptions for submarines.
If you are a power that is not yet at war with another power that is in control of a strait you may ask permission to go through it as well.
Submarines may go through the Gibraltar strait regardless of who controls Gibraltar. This is the only exception. Just in case you didnt know.