I’m glad you found a solution. By the way, after re-reading your post I realised why the driver node was not working for you.
The datapath has to be the datapath of the bone, not the datapath to the property you want to be driven. You specify the name of the property in the “Property” socket. And right now that node does not support drivers for only one channel of a property, like you wanted. I’m now working on a reworked/advanced version of that node that should support that, and adding multiple variables and selecting the driver type etc.
For the outputs to appear, you have to create a variable outside any scope inside the script.
for example, just placing this in the script should let you add an integer socket as an output. I haven’t touched this node in a while, let me know if it’s not working.
my_output = 1
Only some types are supported right now(strings, integers, floats, vectors, objects and lists). And be careful with returning an objects that has not been created inside the tree as it can mess things up if you try to edit them later in the tree.