All my irons are flying off to the right

Block perhaps? Been able to combat it some by opening up my stance. Still not very good control though (although at least its not flying onto the next fairway) and I seem to be losing distance too. Driving and woods are fine. Starts with 3 iron and gets more pronounced as I move down.

What does your finish look like ?

Hmmm. Can't say I necessarily noticed when I was having this problem on friday. Generally though I feel pretty good about my finish. Should I be looking at my finish?

If your Driver and Woods are ok, I bet you have the case of the slides. You are getting away with it when you have the ball forward, and I bet your ball flight of the driver and woods climb upwards in an arc (where you are seeing some loss of distance).

The Irons are blocked because you have the ball in the middle and when you slide forward with your hips rather then just rotating them and staying balanced over the ball, you are moving everything forward and your center is now on your back foot = Block.