yep, you dont want spin on chips so lose the wrists, no matter what length shot you are taking, *force* the club past your hips on your follow through. This will stop you quitting, swing back slowly, its easier to stop that way and makes you less likely to jerk the club down"
If you always follow through to the same point it makes it easier to let the backswing control the distance the ball rolls.
Also, consider using an 8 or 7 iron for the longer chips, there comes a time when you are hitting the wedge too hard to get it to roll without backspin, time to change clubs then.
Roll is your friend!