This is not an answer, more of a comment, however, there is no harm in considering a mix and match here. For instance, you consider still having a sub-transform for the client elements and still having a separate xsd import for the client XML. Just a thought!
I just want to provide something on the What is FHIR part of the question in case anyone else stumbles on this page like I just have! FHIR stands for Fast Healthcare Interoperability Resources. It is built on REST web services, where the URL identifies a resource (a patient, a diagnosis, etc., etc.), the URL /fhir/patient/123, for instance refers to the patient with an ID of 123. The HTTP Verb used indicates what you want to do, GET (returns that resource), DELETE (deletes the resource) and so on. The world of FHIR is massive and I would encourage tools such as google to investigate further.
And as Mark has stated FHIR support is a native element of HealthShare and there are lots of our resources on our FHIR support.
Hi Stephen
The short answer is yes.
The more fuller answer is to talk with your local, friendly Sales Engineer. They will be able to provide you sample code to send and receive via MESH. Or let me know where you are from and I will find out!
Thanks!
Tom.