The thumb rest stroke is still awkward for me, especially when damping is required. Should I be damping with the side of my thumb as I move from 6 to 5 or is there a better way?
I had the same problem it does seem awkward. The first few lessons are all about damping. Basically play the 6th and end the stroke on the 5th to damp it. When playing the 5th loop the thumb back to rest on the 6th to damp that. Generally your playing is good and you seem have good control of both hands.
Charis your pieces are also well played. There are some notes that sound a bit loud, sounds to me like tension in the right hand. There isn't an easy answer for this and there are loads of posts about it on here.