Pinan Godan kata
The first movement of Pinan Godan relies on the same lag of Pinan Sandan with regards to the leg following the core body movement.
What I try to show in the video is that for the first turn, the angle is lead by the core body turn and you should be able to do 90, 180 or 270 degrees for example. It's not placing the foot first and then corkscrewing yourself into position.
On the gyakuzuki, do not twist the hips even more, hips stay facing forward in "shomen" position at the punch is activated by the top right hand corner of the back. It's not to turn both shoulders in a basic way. Do not hold the punch back by having a tense shoulder.
For movement 7, going forward from "musubi dachi" I would say leave something in the tank so you can employ a fuller body turn as you complete the "gaiwan uke". If you go in sideways too early, then you end up just throwing the arms at the last split second.
For movement 8, let's call that the X-block, the principle at work is the same as for the X-block in Pinan Yondan - the body passes through the hands which end up in the "hikite" position by the side of the body from which to execute the X-block. Do not forcefully pull and snap back the fists. Goes back to no unnecessary movement, no additional use of extra energy when not needed.
After the jump I will admit that my posture is not great, should be more upright. Am still suffering from ankle difficulties.