Unfortunately, I have pretty much no expertise in zwave. As Chris will tell you, more than half the time when I try to help I end up giving incorrect information.
But, based on this posting from Chris, I think the answer to 1. is that this is not implemented by the binding yet.
There are some statistics on the zwave controller Thing that might give you some of this info and anything in a Channel can be linked to an Item and charted.
I did a quick search through the zwave debug logs and I don’t see anything that immediately jumps out at me as being related to RSSI and the like. And in a mesh network, is RSSI all that meaningful? And what RSSI would be reported? For example, I may have a device with a truly terrible RSSI to the controler but the messages are routed through nodes so the messages always get through. What is more important is the list of neighbors and some idea of how the mesh is configured so you can find bottlenecks and orphan nodes and the like.
Sorry I can’t be of more help.
These sorts of things are always most welcome.