I do not think they are unique. Only the username and password should be Could you please share them in this case? I already have username, password and access key, but I do not have user id. I'll save me a lot of time.
Sure, but you will have to make sure that you can redistribute this code.
Send me a PM and we will sort this out. There's 3000 lines of code
Thanks again. I've just finished the integration (see changeset e8afd5e9ec1b). The main difference is that a shipping rate computation returns an instance of a specific IShipmentTracker (for example, UPS returns UPSShipmentTracker). But we also have GenericShipmentTracker which is similar to your TrackingService class (find an appropriate IShipmentTracker by specified tracking number). This GenericShipmentTracker can be used by offline shipping rate computation methods.
P.S. Testers are welcome because I don't username, password and access key (UPS) for testing purposes