Fidelius Charm

Say if you were in Dumbledore's position, and you've just had a meeting with James and Lily telling them that their infant son and entire family have been marked for death, how would you have dealt with the whole secret keeper business with them?

1. Moody's Magical Eye

In GoF, there are numerous instances in which we see what Moody's magical eye is capable of doing. Barty Crouch Jr., disguised as Moody, was able to see through solid wood, and Harry's invisibility cloak, which is supposed to be impenetrable. Also, if i recall correctly, didn't he see through Harry's robes and compliment his socks during the Yule Ball? So, if Moody's eye can see through all these things, does that mean that, to Moody, everyone looked like they weren't wearing any clothes? That's a really weird thought that has been bothering me for a long time, and I really want to know the answer. Another somewhat related question I had was, how did both the normal eye and the magical eye work at the same time? For us, both eyes function at the same time, but since for him, each eye had a different function, I was wondering how that would work.

2. Owls and Tracking

In OotP, Harry sent an owl to Ron and Hermione while they were at OotP headquarters. Despite the building being protected by the Fidelius Charm, Hedwig was able to reach Ron and Hermione without any trouble. Even in other instances, letters that were sent by owl post effortlessly reached their destination, without the sender having any idea of where the receiver was. From this, I've come to the conclusion that owls can track anyone, anywhere. So why couldn't the Death Eaters in Book 7 simply have sent letters to the people they were looking for, and then set some kind of tracking spell on the owls? Or even simpler: they could've just grabbed broomsticks and followed the owls. This probably wouldn't have worked if the destination of a letter was protected by the Fidelius Charm, but they still could've caught a fair number of people using this method. So why didn't they? Why did they have to resort to less effective measures like Snatchers and the Voldemort taboo?

Bonus question: do any of you have a random side character that you hyperfixate on for no reason at all and come up with a ton of headcanons for in your head? Mine would probably be Oliver Wood; I don't know why, but I've cooked up a whole backstory for him.

I would really appreciate it if someone knew the answers for these questions!

Here are some shocking facts about the Potters deaths:

1. Multiple people were responsible for it: Voldemort for obviously doing the job, Peter for betraying the Potters by giving away their location to Voldemort, and Snape for telling Voldemort the prophecy which caused him to go after and kill the Potters.

2. It all could have been easily avoided: if Snape had never told Voldemort about the prophecy in the first place, if the Potters had accept Dumbledore's request to be their secret keeper, if Sirius (who was the initial secret keeper) hadn't convinced the Potters to switch their secret keeper to Peter, if the Potters had not agreed with Sirius's idea to make Peter their secret keeper,or if Peter hadn't given up the Potters location.

3. Most shockingly of all, still bitter over his past treatment of Snape, the fans took it out on one man (James Potter).

Tell me what you think of all this!

Can a Vanishing Cabinet transport me to a house that is under Fidelius charm?

Did the charm dissapear after their deaths? I find that unlikely. Peter and Voldemort were the only ones who knew the exact location at that point. So how did Hagrid get Harry?

I was re-reading DH earlier and I realized that Arthur Weasley was the Secret-Keeper of the Burrow, and Bill was likewise for Shell Cottage.

So my question is, why couldn't James or Lily be their own Secret-Keeper when they went into hiding from Voldy? Wouldn't it be so much more foolproof?

Were they just too trusting of their friends or am I missing something?

I was reading the Sorcerer's stone and it just crossed my mind that Harry and Hermione and all other people were able to see the Potters' hiding spot. The strange thing is that the house was protected by the Fidellius Charm and can only be seen by the people to whome the secret keeper has revealed its location; in this case, Wormtail. He was alive when Harry and Hermione visited Godric's Hollow and they both saw the house in ruins.

I don't think the charm was broken because the same charm was cast at the House of Blacks and it was not broken when Sirius died.

Does anyone has any explanation to this or is it just a plot hole?

Can you cast a Fidelius Charm on yourself and be your own secret keeper? If you wanted someone to know you existed- could you just leave them a note?

I just realized that Lily and James staying in hiding is kind of like quarantine. Lily and James were hiding from Voldemort. We are hiding from Covid-19. They could only see their family, we can only see our family. They didn’t know when it was going to end, we don’t know when it is going to end, but we won’t die. Rip Lily and James Potter.

The reason Harry’s parents were murdered by Lord Voldemort was because he was able to find their hiding place after their Secret Keeper Peter Pettigrew betrayed their location and broke the Fidelius Charm.

But I wonder why James Potter chose one of his friends to perform the charm when he could have been his own Secret Keeper?