Hi,
Process versioning in general has nothing to do with Camunda fox and is of course par of Activiti.
Hot deploying process bundles in JBOSS is something we don't support yet, but we might put it on the roadmap if there's enough demand from the community. Activiti has an OSGi module that supports hot deploying service task and process bundles. You can use for example Apache Karaf for that.
You already get REST support by default with Activiti. If you want to use web services you can just create a simple web service frontend on top of your Activiti Engine or your process instance logic in specific.
Best regards,