Pro tip: Coinstar wont take a cut if you get it as a gift card. The times I've used them I just opt for an Amazon Gift card or one for the local grocery chain that I'm already going to be spending money at.
That's, uh, taking a cut, albeit a smaller one. You'll lose the cashback or other rewards that you would've gotten for using a credit card. Gift cards can also commonly be obtained for under face value.
If you don't have a bank account then it is a good deal to change for free. I doubt those without a bank account have credit cards with good cashback deals.
Yup. Last year I got rid of a whole bunch of coins that were lying around. I took it as a gift card for the local hardware, then went over to the hardware and spent the money.