The punch should focus when the foot touches the floor and should be relaxed by the time the stance settles. There will be vibration in the stance after the foot hits the floor that will take a brief moment to dissipate. You focus during this time. Keep the hips squarely to the front throughout the step. Do not try to cock the hip back and then wiggle the pelvis on impact in an attempt to create any vibration.
Vibrations happen on their own.
Down Block - Turn 180 degrees to the rear looking over the right shoulder. Step the right foot back to the left, fold the arms for the down block as you pivot clockwise, and then unfold them in a burst to perform the block as you continue to pivot to the right performing the down block. You should finish in a front stance with the right foot forward. Do not turn the way Kanazawa demonstrates in his Karate Kata Zenshu books. He reaches back with his foot, as if testing the temperature of the water, and then pivots on both feet.