So in the unlikely catastrophic event, your maximum loss will be 0.0025BTC.
Maybe per individual the maximum loss would be 0.0025
BTC, but over your entire userbase this could equal a pretty hefty incentive for you to disappear with the funds or for a targetted attack. Are you prepared to refund these losses? It sounds like, you're saying the maximum loss is .0025, because you will not be compensating this if it is lost.
Payouts are handled by ZPool and not by us. ZPool.ca has been trusted by thousands of miners for a long time.