Hi Paul,
I have been thinking of some similar types of options as when I think of ways to extend and use discourse, I keep on wanting the discussion to be about something or collaborating with something.
I’m sure it’s possible, but there are definitely some aspects to really think about.
The first and most obvious concern is the layout. You definitely want any layout you create to work somehow on a phone in portrait mode. Space gets tight pretty quickly if there is a subject, a conversation and a currently edited post, possibly also with a preview. If the graph interface is an interface in and of itself, that could really take some additional thought.
Another concern is how the data is stored, but it sounds like you have this thought out and are going to go with the poll style which I think makes sense. There are other options that I think would get messy.
Finally, one other thing to think about is covering the process of administering this kind of post. For example what would happen if someone were to move a graph post to a non graph thread? There may be a number of admin operations to cover like that. I’m not sure, but those are the things that occur to me.
Please let us know how it goes as the overall concept is worth exploring, though it may be tricky.