Not sure on some of the points, but others are valid, see below.
1. Headlight depends on the spec, they are laser on the PP with full adaptive mode,
2. Again spec difference, they seats are fully electric on anything but the entry spec.
3.I though the infotainment on the ID.7 was more responsive, but I prefer the maps etc on the Merc.
4. Can't comment personal thing.
5. Both OK, but I know what you mean about the on streeling controls they are annoying AF for such a premium car, reminds me of when the ID.3 first came out.
I'd like to get a fully weekend in the CLA to compare, again a lot of Marc/BMW/Audi etc come to what you spec out of the factory. We'd have likely ended up with an ID.7 if it wasn't missing the pano roof for the in stock cars, oh and the colours.