I see that this is a potentially very useful sequence. However, I have a concern or two.
One, from White's view point, is the best local play? I would hesitate to push from behind.
Second, while I see that makes excellent shape, should a (Hane at the Head of Two Stones) be considered as well?
Velobici: If White does not want to extend to in the diagram above or to the right of , then is an error. Rather than hane at , extending or treating the single White stone as light would be the correct direction of play. Without context (other stones on the board) it is not possible to say which is better.
Third, considering this potential (probable?) follow up series, Black may not be gaining as much as possible, either by continuing to push, or playing hane as considered in Question 2.