Absurdities created by all options...
... just a matter of finding the least unintended 'fallout'.
There are some excellent and uniquely British points of logic and simplicity contained within the existing UK Rule5:
C is best since: Clearly it is the Person Vessel Vehicle and Structure which should not be offended against.
fallout: Hovering in your garden or even an airfield is illegal if whithin 500ft of structures (a nail in a post) Ignored in an 'unwritten' way.
Ones actual height above the surface is and should be immaterial - where no offence or danger is caused - which is covered elswhere anyhow! - 'Endangerment'
What is a structure and built up area? these definitions are vague and leave absurd interpretation open: eg. the 50 acres of football pitches (not in use) when 'attached' to a built up area is considered part of the built up area ( so subject to 1500ft PART) even if it is open country leading up to them.
'Landing and T/O in accordance with normal aviation practice' - is a great phrase - no it obviously does not have not be a 'licensed or govt airfield' - quite right too! Yes they should be 1500ft exempt.
The 'in the event of the failure of a power unit' only sounds sensible - but it's just a cheap jibe against the single engined - particularly in those cases where the chance of that engine failing is not relevant. Where really what counts is your chance of being forced to land in general.
The greatest rules on which so much depends are the:
Unwritten 'parts' of rule 5:
U5i: Try despatately hard not to annoy people. For this is still possible within the rules.
U5ii: Fly a reasonable distance from Chequers 1500ft ish.
U5iii: Any sensible interpretation of 'congested area' and 'structure' are ok provide you are not in breach of rule U5i.
So a re-draft of the existing rule (in fact all the rules) into English would be fine!
FARs are legible so US pilots know them.
In the UK you just had to know 75% of some of the really obscure ones once - 20 yrs ago. And obey Rule U5i (otherwise there is always a catchall rule under which you can be 'got'.)
(I despair.... end rant)