Winner Payout:
Each day, 1% of the jackpot is split between all players with jackpot (daily) bonus points in proportion to their amount as a percentage of the sum of all qualifying points.
Daily jackpot bonus points are reset to 0.
Each week, 10% of the jackpot is split between all players with jackpot (week) bonus points in proportion to their amount as a percentage of the sum of all qualifying points.
Weekly jackpot bonus points are reset to 0.
(I think this will allow the jackpot to grow nicely.)
This won't allow the jackpot to grow nicely. Percentages are too high. Maybe if the weekly jackpot bonus points are reset to something non zero.
Incentive for player to donate 1/2 stakes:
Players that donate 1/2 their staked income get a x2 multiplier on jackpot points they earn. (Up to a maximum of amount invested)
I don't think this is really an incentive for investment. It's just a bonus for gambling, and its not even +EV.
EDIT: I probably sound really harsh. Interesting way of combining the ideas.