Yes. I have identified problems in some of our recent refactorings that have broken error handling on the client-side. I have now pushed a set of fixes out in our lastest 1.3.0-SNAPSHOT if you want to give them a try.
It should address 1, 2, and 3. Now concern 4 is supported, but the exceptions must be exposed to the bus via normal serialization rules.
Transport related exceptions should return TransportIOException.