Malcolm,
Use the WAB to initially set up the Queries that you want in your app. Once they are initially set up the config_json file will be populated. From there you can change the alias names, query name, specify the specialtype (link, image, none) for fields. These are the things that don't seem to be saved in the WAB UI. You can also change the images to something more appropriate than the limited set you have to choose from as long as you use this code. You can also tweak the size of the image.
"resultsSymbol": {
"angle": 0,
"xoffset": 12,
"yoffset": 12,
"type": "esriPMS",
"url": "http://someURL/someimage.png",
"contentType": "image/png",
"width": 18,
"height": 18
},