I guess I have to go along with that people A and E are in local FORes. I'm kinda thinking they are not though.
To be clear at the risk of sounding pedantic, all 5 are in local frames of reference, but only A and E are inertial. You are completely correct in that regard - the two are completely equivalent and no experiment either could do would tell them otherwise.
The problem with saying a guy on the surface of a planet is accelerating upwards is because the only reason he feels a force is because he is being accelerated downwards into the planet so a normal force arises. That is the only reason why he feels a force. If he had no acceleration due to gravitation then he would feel no counter-force.
This reveals the nature of the problem here, I think. The problem as I see it is that (correct me if I'm wrong) you're saying that the guy on the planet can't just feel a force upwards with no apparent cause - something has to be 'pulling' him the other way. This is, in the sense that we established before, incorrect - the guy could have 'fallen', by which I mean experienced no forces, to the surface of the planet without knowing it (accelerometer reads zero until contact) and as such the 'motion' caused by gravitation is meaningless - after all, motion itself is only a meaningful concept when two observers tell each other how they appear to be respectively moving.
This is no different to a guy sitting in a rocket until the engine is lit - a sudden and inexplicable increase in force which could be either due to gravitation or to thrust, with no way to distinguish between them. We have to be clear that gravitation does not
cause acceleration - gravitation
defines the framework that we measure acceleration in - that is, the geometry of space-time.
No, I know gravitation causes acceleration without a force. Einstein did not get famous by stating 5=5. He found two totally different situations and was able to set them to equal when being locally. They don't have to be the exact same thing as each other, they just have to be equal.
Without wanting to sound patronising, when Einstein wrote E = mc
2 he
was essentially writing "5 = 5" - the fact that until relativity came along the link between '5' and '5' written in different colour inks (for want of a better analogy) wasn't made explicitly is a testament to his genius for conciseness.
As for the principle of equivalence, the same thing can be said there - by stating that again '
5' is the same as '
5' in any meaningful sense, he revealed a deep insight into the nature of space-time. If you are in free-fall, you experience no local gravitation (even next to a black hole). If you are accelerating, you essentially distort your local space-time. Obviously the cause of the two is different and must be explained as such, but their observable effects are indistinguishable and must be treated as such.