Yes, HTTP / HTTPS requests can be proxied this way. Any CF IP seems to work. HTTPS only works if the target hasn't disabled Universal SSL (i.e, they have a TLS

Yes, HTTP / HTTPS requests can be proxied this way. Any CF IP seems to work. HTTPS only works if the target hasn't disabled Universal SSL (i.e, they have a TLS cert provisioned on Cloudflare's IPs).