I've tried this in QGIS 2.14 LTR, 2.16 and 2.18, and a fresh install of 2.14 LTR on another PC.
My questions are:
How do I get the CRS selector dialog to open? When opening a raster image, I get no CRS selector dialog, as these two guides clearly show it should. Instead I get an internal error message "CRS was undefined: defaulting to project CRS". I can select the right CRS from the project properties, but the second issue is unchanged.
How do I make the georeferencer output destination coordinates? When adding control points in the Georeferencer, their coordinates just show 0.00. Predictably, the image will fail transformation.
Settings -> Options -> CRS -> CRS for new Layers
set toPrompt for CRS