They wanted to be able to testify under veritaserum that they had not been profiting.

I do not recall Harry or Hermione requiring adult input to enter their contract except for McGonagall advising them on the form and possibility of such contract. Granted, it was overseen by the Wizengamot and their legal guardian, but if they could not have done it legally by themselves, we should have seen Dumbledore's explicit approval instead of just lack of overruling it.

A: "<statement>. [<suggestion/imperative to behave accordingly>] Do you understand?" B: "I understand."

I claim that in normal human communication that type of exchange is viewed as B accepting what A says, unless B somehow signals explicit disagreement. Then, if B knows this, and assumes that A thinks likes this, and only explicitly affirms understanding while withholding knowledge of their disagreement, B is at the very least deceiving A.

Of course Moody should know to be more paranoid in what he forbids Harry from doing. Especially with him having witnessed Harry showing cunning and paranoia on a level he finds promising.

Do we have evidence that his Eye sees through things like that? It sees in all directions and through hiding-magic but does it see e.g. through walls?

From what we have seen so far, it would rather appear that Harry's signature is just as valid as if he had been an adult. He can be overruled by Dumbledore but it is not required that Dumbledore signs the papers for him.

"Do not sign anything that Lucius Malfoy gives you," Mad-Eye Moody said. "Nothing, do you understand me, lad? If Malfoy hands you a copy of The Wonderful Adventures of the Boy-Who-Lived and asks you for an autograph, tell him that you've sprained a finger. Don't pick up a quill for a single second while you're in Gringotts. If someone hands you a quill, break the quill and then break your own fingers. Do I need to explain further, son?"

"Not particularly," Harry said. "We also have lawyers in Muggle Britain, and they'd think your lawyers are cute."

That's close enough to a promise. Besides, Dumbledore could have made him promise more explicitly off-screen and this is just Moody doing the same independently or reiterating it.

We do have RSS.

I think a language/country subreddit or language-tagged threads might better solve the objective of a country/language specific mailing list.

Blaming the Pioneer Plaque for the progressive degredation sounds like it makes sense at first, but the point of the Pioneer Plaque thing is that this Voldemort is supposed to be smarter than canon Voldemort, and a Pioneer Plaque horcrux superior. That theory makes the Pioneer Plaque horcrux inferior.

Smart people still overlook things. A lightspeed delay problem in horcrux syncing would not have come up ever before, so it could have been easily overlooked even by a very smart person, especially one that is not scientifically oriented. If he had been more scientifically oriented and been otherwise interested in Muggle space programs, this possibility might have occured to him and he could have tested it with the moon missions, if he had come up with a way to detect anticipated problems.

The spell hides current environment, except for a floor/ground "disk." It could be oriented so that the sun is down and thus out of sight.