I’ve had similar thoughts about Jakku as you. It’s conceived as a junk planet but comes across basically as just a desert planet. Now, I don’t really have much of an issue with it, as I think the desolate landscape adds scope and heightens Rey’s isolation (and scavenging skills). Your suggested ideas are cool, but ultimately I fear they are probably hard to implement and ultimately not worth it. I feel like a potentially simpler “fix” for Jakku would be to recolor the sand to something more junky, like grey or brown.

With the others, again it’s not really something that bothers me, but the ideas are cool and could work well.