Sometimes I do things for non-economic reasons. I thought the rise of pool hopping mining clients would be sufficient to drive people out of "unfair" payout methods. Maybe a hop-pool could do it. I like your thinking of 50% cut of the "bonus". Since determining all the bonus amounts could be challenging (no way to know hop "bonus" other than after the fact and that is subject to variance) then maybe pay 100% PPS and at end of the month issue a "bonus" payment based on the pool's revenue - PPS payout. It would be less risk to the pool operator and worst case scenario it is a 0% PPS which isn't bad.
Yeah, sounds good. How would the bonus be divided between the miners? Would it be "fair" to distribute it proportionally each day? I expect this way that if the difficulty changed in the middle of a day that you'd have to split the day into two parts and distribute proportionally on each part.