Does VPN protect my whole device?
No. The built-in VPN only hides your IP address and location while browsing in Firefox. It does not protect traffic from other apps on your device. For full-device protection, we offer Mozilla VPN.
Since you said you don't need it for torrents, I thought this would suffice. But I realize now you still want to hide your IP while torrenting.

Nothing really meant to use as a daily driver. There's some sort of WebView implementation in Tauri and apparently a not-really-maintained browser project: https://gitlab.com/verso-browser/verso