Why only 0.5*diff on PPLNS? Variance would be much lower with a higher N.
Also do you account for difficulty changes in your payout calculations?
it would take weeks to get paid completely on your shares with even 2*N because the pool is small
Oh well , did any of the great pools start from 1000 workers and 1 T/Hashes since the start ?
Off course it is a new pool and still small , but with a lot of expectations and faith.