Photoshop ❌ Microsoft Paint ✅

your (very expensive) license is tied to a USB stick

Not true. You can link it to your Unraid.net account using Unraid Connect: https://docs.unraid.net/account/link-key/

Sure, it’s not perfect, but still the best option for beginners.

Unraid is great for beginners.

HomeBox is perfect for your use case. You could also try InvenTree, but I think HomeBox is going to better suit your needs.

it would all be P2P backed up

It literally is. https://help.archive.org/help/archive-bittorrents/

Any FOSS Linux/Unix shell, bash, zsh, fish, tcsh, whatever, is a million times better than cmd or the early versions of PowerShell. Yeah, I know, PowerShell Core exists now, and it’s even open source and cross platform, but it still sucks.

It reminds me of IrfanView, but I’m sure it’s better than that

I like LibreWolf, it’s a privacy and security focused fork of Firefox.

But I’m really looking forward to Servo, hopefully it becomes usable one day.

Most ROMs like LineageOS and CalyxOS drastically weaken the security of Android, so that would actually make sense. GrapheneOS has far better security than AOSP, the Stock Pixel OS, or basically every other version of Android that you would find pre-loaded on a device. https://grapheneos.org/features#exploit-protection