Some background to me taking this Challenge. I've edited Wikipedia for a short time mostly on topics related to the philosophy of religion. One of my most pleasurable editing experiences was the discussions that ensued after I removed the criticism section from "atheism". By way of to Richard Dawkins, and The God Delusion, I reached the intelligent design articles. There, the atmosphere is different, I felt people paid too much attention to what my intentions might be for suggesting to neutralizing the tone of the article per WP:WTA.
The point of WP:AGF is to judge contributions by their merit and not by the intentions of the contributor.
My wife is not a coauthor edit
Of course, we go with published sources. He has no legal case, but it doesn't hurt to kindly explain the purpose of our policies to him. We ask about the facts, ask about how come his own web-site states otherwise. No matter, how this proceeds the fundamental theme in my reply is going to be that nowhere do I have to assume he is honest in the face of obvious evidence, the point of WP:AGF is that telling him he is a deceitful liar will not help anyone. Most certainly not us.
My town's library edit
Ask the person for help to improve it. Explain that we need sources because otherwise someone could come and write terrible things about his precious library, and how could that be verified?
Prod, AfD, etc...
I am the best edit
Here, I would give in on a few points. This is a living person. And I believe that having had something bad written about you in some newspaper way back, is not the same as that information appearing a google-topping bio that some anonymous people write. Wikipedia can ruin people's lives, if we go too far with investigative journalism, that's not our job. I don't think it is appropriate to dig into his dark past. I'm therefore very careful with biographies.
But I would write about what is well-known about the cheating scandal, I would include notable critical reviews of his books. That's all our readers need to know. On the other hand, I would not allow any whitewash. If he wants to be called a Professor, I need reliable third-part source for that.
Irrespective of how we deal with him, the point is that although I know he is a charlatan, pointing that out on talk pages would achieve what?
Arrow of Time edit
This is perhaps the most relevant case. What would I do? I would go crazy. I would totally explode and say nasty things to him. Then I would feel bad, I would be pissed off at myself for saying such things that I would never say to someone in real life.
I doubt anyone who cares about Wikipedia could stay sane in such a situation. I think the only way is to care less about individual battles, step back, raise an AN/I thread early, rather than late, asking more admins, especially supporters of CIVIL/AGF, to come and deal with it. Surely, real life challenges are even better than this test, although I think this test is very well made.
Ghost in the machine edit
Well, well, well, this is again very difficult. The question of whether such electromagnetic phenomena occurs is clearly in the domain of science, and that is the neutral point of view. WP:FRINGE and WP:PARITY are policies that can be useful.
However, mocking these editors beliefs, as ridiculous as they may be, I think is not as effective as just insisting on reliable sources. Appealing directly to WP:FRINGE may not be good way to deal with these people. Saying things like "We can't state this as fact, see WP:FRINGE", will lead to responses appealing to WP:SPOV.
Rather than directly appealing to those policies, one could try saying, "This is a statement about electromagnetic phenomena, we would need something from peer-reviewed journals on the topic to state this as fact." But I think it is naive to think that this would help much. Once more, you might have to just ask for help early rather than late. I would certainly be willing to help.
But in the end, this is essentially a non-answer. I fear that if we went only with professional conduct and not some serious edit-warring, it would lead to many articles deteriorating.
Take me to your Leader Extraterrestrial Shape-shifting Reptile
edit
First of all, the moment a person starts to denounce Wikipedia, its principles, and its key people, it calls for banning. This is part of the rules and has nothing to do with whether the person means well or not, but there are acceptable ways of presenting criticism and there are unacceptable ways.
The more serious case is if it is not such a blatant troll, but say a group of 50 editors, who always remain WP:CIVIL, but keep inserting this stuff, then we are in trouble. I believe the biography of top US politicians would be fairly safe, but they could achieve a cultist consensus on some lesser watched pages. We have no way of dealing with this, do we?
I think what should be done in the future is to use WP:FLAGREV to deal with such matters using a large group of long-time Wikipedians to reach a fairly neutral version, then the article is flagged as a quality version, something along those lines.
Related to a saint edit
If this Wikipedian is otherwise a positive contributor and well-respected, I would stay back and contact some of the good people-persons on the Wiki. I think we all know that RS overrules any editor's personal feelings. The question is how this is implemented and what is said to the editor in question to not hurt their feeling. I would step back, but I think there are people, who can do this well.
I make my own rules edit
Whether he means well or not, he is warned that this is not acceptable and then banned. Assume good faith does not mean you have to actually assume he means well. It means the most effective outcome is reached by ignoring intentions altogether.
Conclusion: My view on AGF edit
The Greek gods did not care if someone meant well or not, it was the deed that mattered. It's not about assuming good or bad faith, it is about ignoring faith altogether and focus on the encyclopaedia.