No. Both CUPS and Netflix work perfectly fine for me on Arch.

You’re probably confusing it with Alpine.

Despite the memes, Arch isn’t that hard to install nowadays. The Wiki is stellar and archinstall is a thing (as well as EndeavourOS).

But Debian testing is a fine choice as well, of course.

In my experience, once you’ve got Arch set up, it less work to maintain than Manjaro. On Arch, you have noticeably more frequent, but smaller, package updates. On Manjaro, compatibility issues with the AUR may occur, which happened a few times for me, while that won’t happen on Arch.

Keepass allows you to use a passphrase in combination with a randomly generated keyfile. You only need to copy the keyfiles to your devices once (not via cloud services, obviously). Your actual database can then be synchronized via any cloud provider of your choice (hell, you could even upload it publicly for everyone to see) and it would still be secure.