Wow, thanks for the nice showcase!
I don't know what it is but the timing of 8 doesn't work for me. I have yet to beat that jump. The rockets just don't line up.
Hmm, I didn't expect that jump to cause such a headache. Well, the way I do it is to walk off, then rotate by 180 degrees (counter-clockwise) in such a way that I complete the rotation as I touch the green ramp.
To find out why the rockets don't line up, you can shoot 3 rockets at the same spot, followed by one at a different spot. If the last rocket explodes first, you were too fast - and vice versa. Maybe that helps.