I recommend you read Pjnt of www.fanmadefallout.com's guide to Dialogue_Training. You can download the Tool here. This is the first window you see when you fire up the tool, and is used to play through dialogues to check for errors and consistency, or just to hear what the NPC has to say. You can start the dialogue with the 'Run dialogue' button. This will play the node selected in the 'start node' field. Selecting a node and pressing 'Clone' will create a new node identical to the selected. This is a quick way to make multiple nodes with the same player options but different NPC text.