Looks like you guys are doing fine for where you’re at. Just keep chipping away.
With regards to driving, the only thing I would say is it looks like your son needs a little work driving in traffic. But that’s normal for kids, especially ones who have just moved up. It just looked like he was waaaaay faster than the CRG kart and he rode behind him for two laps or so when he could’ve gone by at least a dozen times. That’s especially bad in qualifying when you need open track, and he caught the guy right during his prime laps on his tires.
My advice there is not to force it though. Let him build the confidence to make a pass somewhere other than the straight. If he starts to try and force moves he’s not confident of, then he’ll probably misjudge something and end up making contact or going off. Just take it slow, it’ll come to him as he gets more comfortable.