Ah, but Rustle (and Evo),
If... no other IF rules are broken (including quadrantal) then I can't see why you couldn't fly it down to MSA
What about the 1000' rule? That's where I'm not sure. Because the rule doesn't count if you're making an approach. Do the "track and height profiles on this scrap of paper" count as an approach?
To answer your question about descending through the cloud over the sea, no I don't believe that's legal. Again, it's the 1000' rule that's going to catch you - there is no way you could reasonable describe what you are proposing as an approach, so you are illegal under IFR, and you can't be VFR if you're in cloud. Doesn't make any different if you're receiving any radar or non-radar service from anyone. At least that's my interpretation.
(Looking for the exact text of the low-flying rules right now to paste in here...)
FFF
--------------
Edit: the text of the rule can be found
here, on page 249 of the document, under rule 29:
Without prejudice to the provisions of rule 5,in order to comply with the Instrument Flight Rules an aircraft shall not fly at a height of less than 1000 feet above the highest obstacle within a distance of 5 nautical miles of the aircraft unless:
(a) it is necessary for the aircraft to do so in order to take off or land;
(b) the aircraft is flying on a route notified for the purposes of this rule;
(c) the aircraft has been otherwise authorised by the competent authority;or
(d) the aircraft is flying at an altitude not exceeding 3000 feet above mean sea level and remains clear of cloud and in sight of the surface.
Therefore, I would argue that in my scenario, (a) comes into account, because it is necessary to fly below 1000' in order to land.