I think Gree needs to decide whether to do a scraps contest or a hero expo/fp/coli contest. Otherwise, they need to significantly rebalance the points.
For instance, in my casual gameplay this weekend, my points were as follows:
All purple/orange points: 88%
All enchantment: 2%
All FP/Coli: 3%
All Expo: 7%
I would reckon this was similar for most players (with top 10% rank having much higher scrap percentages). This means there is little to no incentive to participate in the non-scrap categories - why bother?
Suggestions: Either drop them entirely and use them for mid-week contests or significantly boost the point values to make them relevant.