It would allow you to access your entire network. Other computers, devices, cameras, etc.
imo it’s better to have it on a separate device but if your router supports it, go ahead!
Yea, though you’ll only want to do it from trusted devices. Ie. your laptop or phone.
Unraid has a wireguard server built in.
Does it work if my isp uses a double nat?
It is built into the kernel, but you still need the plugin for webUI management.
It even tells you to download the plugin in your link…
As long as there’s a free port that’s not blocked by your ISP then WireGuard can run all traffic trough that port.