Old laptop as a server is viable and not unheard of. They’re generally low power consumption, and have a built-in KVM and UPS.

Depends on your VPN provider and use case. I’d recommend against Tor-only if you want normal people to ever see anything you blog. You’ll need static IP and/or dynamic DNS if you want it to be reachable with any kind of reliability. Doing it over VPN requires your provider to support port forwarding, which not all do.

Again, depends on your use case. It’s generally a good idea to disable unused services. Worst case it goes down while you’re on holidays or something and you can’t get it back up for a while. Can you live with that?