Hi; thanks for your interest in SwitchYard!
Reading through what you're looking for help on, most all of it is specific to jBPM, not SwitchYard. I think that you will get more complete answers/options if you post in their discussion forum area, here: https://community.jboss.org/en/jbpm?view=discussions
That said, let's talk about your "Challenge 3" a bit. Using the POJO approach to call out to that external webservice is an option, for sure. However - and I'm not sure which is better for your particular use case - you can also use SwitchYard to do that. SwitchYard supports soap bindings inside "composite references", so it can call out to an external webservice in an outbound fashion. Documentation for this is available in the Binding References with SOAP section of the documentation. You can also see it in practice in the camel-soap-proxy quickstart in the SwitchYard distribution.