Your sugar content isn't unusually high for a yeast leavened dough, but you already know that.
If you've got the space and time to accomplish this simple build, I highly recommend it. This was the finest pizza cooking apparatus I've ever used; even more so than anything pro I've used in high-end kitchens and a pretty stellar pizza restaurant.
http://thecobovenproject.blogspot.com/
Once built, we used the HELL outta that thing! We tweaked the design a little, including a much smaller opening and making a small wooden door/plug to keep the heat in.