Remember the formal techniques are for reference, a training tool. If you need to step forward in order to close the distance to make the technique work then do so. Try practicing this technique for a punch from the Rt side or the Lt Side, either closing or increasing distance.
As for the block to a straight punch; a block is not disigned to be a counter to any one attack, but to cover a certain part of the body from whatever attack.
Actually at some point in my training I condenced this technique into a 2 count. The stance transition, the kick and the block are all simotaneous, theory being, I get my kick in faster impaling him in the groin, his punch is aimed more toward my left shoe than my head. I have actually used this in freestyle, althought my kick is targeted a little higher, and the follow-up is a ridge-hand.