I think he was mainly referring to 2D as far as the primary combo starter, as it knocks them straight up. There's possibilities with all of them though, check this page out for more: http://s1.zetaboards.com/blazblue/pages/bangcombolist/
Are you using the d-pad for 2369nails? Analog? I don't know why I have such a hard time with it. Maybe the 360 controller is better for that, since the d-pad rolls kinda.
It's too bad we're on different platforms, I think we could help each other out a lot.