Do most programs pass refunds/cb's to the affiliate?
 

Is it common to do that?

it should be normal, since refunds/cbs are part of the deal

There are very few programs that will eat your chargebacks/refunds. The fraud for programs that do must be phenominal.

all revshare programs make affiliates take the loss from refund/chargeback...
and most (all) PPS sponsors take the refunds/chargebacks themselves... (they probably just shave the next sale when you get a refund/chargeback though, lol)