Sounds like you’ve done a bunch of research! Since you’re using unRAID, setting up your services shouldn’t be too difficult.

For your torrents and VPN, there’s a few in the unRAID community store - I’d recommend qBittorrentVPN from Binhex - here’s the documentation for setting up their VPN-enabled containers.

For Headscale, I don’t have any direct experience but unRAID has a decent Wireguard plugin, and should get you up and running in a pinch.

And for your self-hosted services (especially Bitwarden) ensure you’re not exposing this on the net, by VPN is the only option I’d recommend. Even so, I prefer to use Bitwarden’s hosting with a family plan, for peace of mind and resiliency. It’s also much easier for my family.

UnRAID is a great place to start - it allows you to scale cheaply as you need and is easier to fix mistakes. Good luck, and happy homelabbing!