You are right.
We might expose the signal as an admin operation. But that should not have priority. Can be skipped.
Yep, one of the lesser used features. Certainly skipping for this release. In the future if the taskinstances related to a token are taken into account it becomes more interesting.
YOu can configure TaskInstances to be canceled if you leave the node via signal, so in some cases it might make sense, but it is really more an admin use case and less important at the moment...