I have specified 2 sec as a lead timeon my snipe. Is that unrealistic??

As long as the item doesn't end on an hour, quarter hour or half hour it should be fine. Since that one ends at 8:43am it will be ok.

Smaller lead times do increase the risk that the snipe isn't received by eBay in time. We do a lot of 2-3 second snipes a day and few are missed. Less than 1 in 1000.