So far, your argument Seems to have separated the Commandment so that one part refers to God and one part does not.
I think you may have misunderstood Rod on this point. (And Rod, please correct me if I'm wrong -- I'm just trying to track with the discussion here.) As I understand Justin, he arguing that the second commandment is actually two commandments: one preventing us from making any images of God, and another preventing us from using these images in worship. As I understand Rod, his argument is that there is only one commandment, which forbids making images for use in worship, whether of the real God or of false gods.

So, Rod believes that the second commandment forbids, say, making an image of a tree, calling it "Bob the mini-god of maple syrup," and worshiping that. But Justin's argument seems to be that the second commandment does not forbid this -- that it only forbids making an image of a tree, calling it "YHWH," and worshiping it. But if the first part of the commandment only forbids making images of God, then where is the commandment forbidding images of false gods?

I think we must be miscommunicating on this point, since I doubt Justin would really say that. But he seems to have explicitly denied that the first part of the second commandment applies to images of things other than God. So, my guess is that Justin's argument is that the second commandment forbids: (1) images of God, and (2) worshiping God and/or false gods through the use of images. But this would seem to commit the very error to which Justin objects, namely dividing the commandment into one part that refers to God (i.e., don't make or worship images of God) and one that does not (don't worship images of false gods). I'm personally not opposed to complex commands with different parts. But in light of Justin's objection quoted above, it seems that he is.

It seems to me that some clarification on these points would help us communicate better.