Yep. You've got it. I spent about 30 minutes with iDraw (£16) to make the dial, pasted into a ThingStudio screen, and inserted the helpers to animate it. I'm an SVG noob, but it took me about an hour in total. The code to drive it is two lines with ThingStudio. You can actually do it today on ThingStudio, but we don't support these as libraries, you have to paste in the code each time, that's what the new version will allow. I just pasted this into one of my screens on the current version http://www.thingstud.io/screens/MTmhk7LwiN58ijKZP, (you'll need to signup to access it), the second slider down will move the pointer.
http://thethingbox.io/ do an SD card with a preloaded node-red, node, and mosquitto, but so far I've not been able to persuade them to upgrade to Mosquitto 1.4, which supports websockets. :-( . I suppose I could go into competition, but I'd rather they just upgraded their build...
I totally get your point about MQTT - did you ever consider just selling a Raspberry Pi with MQTT installed? It might not make you much money but it'd be a good way to get people started with Thingstudio.