Yes, all is available. See the documentation
It would help if you provided a link or two...
I'm not sure of the answers to all of this.
My initial response would be no, none of it is implemented, but if you're right that it's all in there, I must just be ignorant.
The documentation on JMS-implemented nodes reads "Not Yet Implemented" (http://docs.jboss.org/jbpm/v3/userguide/asynchronouscontinuations.html#jmsforasychronousmessaging).
Yes. It will be really great if Ronald or someone posts some links on these features which mention whether they are implemented. Thank you.
Regarding the links... the thing I forgot to mention is that it is all in 3.2 (currently in beta). The docs on the site are still for 3.1. So get the 3.2 staterkit with the docs in there and be surprised.... :-)