I'm a bit concerned about the disparity of the rewards. If too little people are rewarded, it might turn away many from forecasting.
This is a good consideration, but keep in mind that you still take a reward even if your forecast is far from the right amount (like 50%). I also took 0 QVT, but I had overestimated the project so it is right that I did not take any.
Perhaps a minimum, at least to pay the fees, should be given to everyone (a sort of airdrop of QVT, it's a good marketing move too).