To answer my own questions now I have the official rules:
From my previous list:
Is there a naval battle board?
No.
Can attacking ships retreat from a naval battle, or do they stay in what is now a contested SZ when they break off the attack?
They stay in a contested SZ = sitting ducks.
Where can Battleships repair, and for what cost?
In a SZ containing a NB you control, no cost.
Do damaged BBs fire & move accordingly, i.e. at 2 rather than 4 (always liked this rule).
No.
The UK report appears to contradict the Russian version that stated ships can only be built in original home naval bases; does this in fact extend to captured bases?
No, original NBs only, the tt concerned must be controlled or contested.
What happens to mines adjacent to a naval base that is captured, or whose original owner is knocked out of the game?
They are neutralized.
Are submarines able to contest an amphibious assault if the incoming transports have no combat ships escorting them?
No.
Is there a limit on the number of Commonwealth units that can be placed in Bombay every turn?
No, just no navy.
If the Allies control SZ 20 do they have free access through the straits from SZs 21 to 19/17 regardless of Turkey still holding Constantinople?
Rules don’t seem to say.
Similarly, does control of Egypt block movement between SZs 19 & 28?
Yes.
Does SZ 30 have any function?
No comment, Sir.
Can ships carry units of their allies?
Yes
Can fighters fly over neutral tt?
They can fly over any tt.
Can fighters make an attack on their own (without ground forces?)
No.
Can fighters of an allied power join in air combat in an attack within a contested tt?
No.
Does, in fact, at least one infantry always have to be involved in any attack on a land territory?
Yes.
Are the Allies permitted to invade non-aligned neutrals? I foresee big problems for the CP if they can, particularly in regard to Persia and Norway being used to feed U.K. units into Russia (I assume the western Allies are allowed on Russian soil).
Yes.
_What happens to units of all players in Russia when the revolution occurs?
If Russia is out of the game, can the other Allies take control of Serbia & Romania as if they were non-aligned neutrals?
Similarly, if Russia had been given control of, say, Holland, does this tt now have an invisible force field preventing CP attacks, or does control transfer to one of the “active” allies?_
RR rules need a complete rewrite.
Do minor Allied (Belgium & Portugal) and Spanish colonies have forces, and if so how and when do they come into play?
No.
Are the conditions of a power whose capital has been lost the same as in previous Axis and Allies games, i.e. the occupier gets the player’s saved money, the defeated power cannot build new units nor collect money unless liberated, but can still fight with surviving units?
Yes.
Are submarines vulnerable to mines in the same way that surface ships are?
Yes.
I’ll see if I can find the answer to the Constantinople Conundrum.
Time to draw a bath…