I was in that run group! Didn't spot my car in the video though, bummer.
I've been letting the lines sink in too (August was my first time on Lightning), and I think I have a lot of work to do on turns 1 and 5. I tended to over-brake for 1 and drive point-to-point for the entry at 5 as you mentioned. Should be carrying a lot more speed in both places.
I'm going again in October (with the NJ CCA chapter) and I hope the weather is as cooperative as it was in August. I'm going to be on different rubber this time and will be learning all over again