Port forwarding is normally to overcome inbound issues.

vPanel should show if your device is registered, but you would need the account and password to login. https://secure.voipo.com/features/devices

Your account is the number you selected when you signed up.

Do work with VOIPo support, they have many tools, and information that a mere user like me would not have.

X-lite should fail until your HT502 registers for the first time. Then the credentials at https://secure.voipo.com/preferences/softphone should work.