By far the the thing that needs fixing (probably already in wiki) is the traffic popup. I drove today with Waze running and I can't keep my eye glued to the little cell phone screen for obvious reasons. I bet they would be astonished at the false reports being generated by this popup.
I stopped at a bank and while I was conducting my business the popup came on and before I got to hitting "no" the report was generated. it sure worked because when I left, the road I left was red.
Traffic was moving fine.
And by the way, Do you know how small that "no" button is on a Droid?