Looking at the inconsistency in the short times, “rookie driver”, and footbrake, I would get a buddy to film a few passes to see what chassis and tires are doing. Then maybe put a more experienced driver in for a few passes. As stated above, you need more laps and understanding on what car and driver are doing before doing any big changes. Foot braking and consistent launch rpm were always a challenge for me without a 2 step, not sure what you are using. Main thing tho, keep having fun.