What I notice is that you are actually better on the touch and go rep then on the first one. On the first rep of a set you seem less stable. My theory is that when you receive the barbell you instinctively tense up your core to absorb the weight, making you more solid. On the first rep you seem too lose/shaky.
Before starting the dip tense up your abdomen as if you were about to get punched in the stomach. And when you dip down push your knees out.