Hi Ian, sorry for the late reply.
If you want to get node red to get a message from pressing a button in ThingStudio do the following.
First create a Feed in ThingStudio that specifies the MQTT topic that you'd like to use. Let's say the feed's title is RedButton and the MQTT topic is /nodered/button.
Next, make a screen that has a button that looks like this
< button data-feed="RedButton" >Boo< /button >
Next make some flow in nodered that has a MQTT input node with a subscription of /nodred/button.
Then connect something, let's say a debug node to the MQTT input node,
Deploy, activate debugging and you should see messages flowing from ThingStudio to nodered.
I'm trying to get a nodered/ThingStudio screencast out shortly.
Shout if you need help.