Is it safe to fire? Yes
Is it something to worry about long term? Probably not. Shoot the gun and see how it goes.
I'm constantly reminding myself these (Airweights) are $500 retail guns. Considering S&W gets about 60% (?) of that... $300 worth of labor and materials... It's a miracle these...
I certainly understand the OP's frustration. I've seen retailers raise the price just as the rebate starts to cover the amount of "savings." I've also lost rebate dollars due to the extremely short expiration dates on the rebate debit cards.
Consider me not a fan.