Thanks for the feedback.
This request has been discussed in depth in several other threads.
It's a painpoint we're aware of and the changes for it will not make it for the CS6 release.
There are ways to work with it, such as what Noel has suggested with the Esc key, you can also use the Enter key (with a vector tool selected) to hide the boundary line, or as you have suggested as well. CMD/Ctrl + H to show/hide toggle.