Screenshots!
Here you can see my work-in-progress of the first run wizard. The help texts still need to be improved but the rest basically should work. Dependent on if you choose "Custom format" in page 3 (unfortunately hidden on the screen shot, but is within the preset list) you get page 4 displayed. The bottom right dialog appears if you hit insert field in the custom format dialog and displays you a choice of fields you could use. Maybe one should change the background color of the help texts to make them distinguishable from ordinary text widgets. So, was quite a bunch of work so far and I hope it payed out.