there is no such thing as a "jBPM server". The jBPM engine works without any server. Only if you want to use the grovnor-tools (for editing process definitions) or the jbpm-console (for executing human task processes) you need to run an application server (i.e. JBoss) and deploy the components.
Have you tried out the demo? There is an eclipse helios installation inculded and configured by the ant script.
Your second question I do not understand. What do you mean with "jpm projet design"? If you mean a process definition it is enough to load and start it with the API. You also can deploy it on your AS by using the govnor repository like shown here:
Hope that helps.