Node-RED is pretty great. I think a wiring interface is a better choice than a block-level thing like blockly.
Which interface do you think is more newbie friendly? My gut says blocks (maybe something a bit more simple/refined than blocky) are easier to grok, while wires allow for designing more complex workflows.
maybe figure out a few common workflows that people would make in riko or node-red, and mock up how they'd work/look in blocks vs. wiring/pipes.
Good idea, what are your workflows?