I only know a bit about the first question, can't help you with the other ones...
You can request two "flavors" of WSDL from a NW/ABAP system. This is related to the fact that the implementation (programming) of the service is usually performed on a different system and by different people than the configuration of the service.
After the service (or rather a service definition) has been implemented, you can get what's called a "design-time WSDL document". This document does not include the endpoint information - it cannot, because that would require technical information about the target system landscape and its configuration that is simply not available yet.
From the service definition, an administrator can create a configuration. This includes the binding information as well as stuff like base URL, security settings, transport layer settings and so on. With this configuration, you can generate a second WSDL document that contains the actual endpoint configuration.