Only at the most superficial level. Fundamentally these are different cases:

• Haiku is a reimplementation from the ground up that happens to behave like, look like, and interoperate with* BeOS. It is a hobbyist product that people are doing purely because they want to and enjoy it.
• ArcaOS is OS/2, minus IBM's trademark, and with some additions by Arca Noae, the company behind it, to make it work on modern hardware. It is a business product focused on legacy OS/2 workloads (and probably a few hobbyists or the nostalgic buy it too).

*Only then 32-bit version.

It depends, but in general, no.

Fictional characters and settings are covered by copyright, and any use of them would be considered a derivative work. But there does have to be some reasonable specificity: you can't publish a story about Harry Potter at Hogwarts, but the mere idea of "a boarding school that trains wizards" probably isn't, in and of itself, copyrightable.

I just received a Librem 5 a week ago. Depending on your use case, it's definitely possible to use as a daily driver. Phone calls and text messages Just Work. I don't mean this to sound like I'm damning with faint praise: actually using it as a phone was somehow something previous Linux phones didn't prioritize, so it's important to mention. I signed onto my Nextcloud instance with it, so contacts and calendar work fine. Same with email (which is just Geary).

Beyond that, though, there are definitely some areas that need polishing. In particular, the camera is essentially unusuable, not because of its hardware but because so much of a modern "camera" is actually the software processing. And there are other things, but really, boiled down, it amounts to the software not quite being ready for prime time. On the one hand it's irritating, but on the other it's potentially heartening: software can be updated if someone does the work.

Notably absent is any cost analysis without "$370bn in tax credits and other support."

It's more than that.

Years ago, an unofficial version of Zork was leaked/spread as Dungeon. The original MUD was literally a "Multi-User Dungeon." More details: https://www.filfre.net/2017/12/games-on-the-net-before-the-web-part-2-mud/

History is simply repeating itself.