1. I can go and look at the Mona Lisa in the Louvre. Or buy a poster, or even a really good reproduction - so good that I can't tell the difference. Why don't I? Because I don't want to hang a reproduction of the Mona Lisa on my wall. Would I hang the real one up if for some bizarre reason it was gifted to me? Yes. Well, no, because of security issues, but if those problems weren't there, then ... yes.

2. The Mona Lisa won't last forever. They'll work really hard to keep it around, but it will eventually fade (or, like Theseus's ship, be slowly replaced through touch-ups and fixes). If the internet is around, and I am gifted Beeple's artwork, I can run my own IPFS server to make sure the image is served up when needed.

3. This is a problem. But ... blockchains are timestamped records. There will be an earliest record. As for your Twitter example - I can start my own social media platform and call myself Paul McCartney. Doesn't make me a Beatle.

4. See 3.

5. Yep - that's the problem with NFTs that point to privately owned web servers. So theoretically, NFTs with IPFS URLs should be worth more. That doesn't seem to be the case. Art and collectable NFTs aren't rational. But then again, why is a Picasso worth more than a Mondriaan? Who knows...