Let me start by saying that I've nowhere supposed or asserted that "God sees us as children". As I understand it, you're an atheist so my argument takes that into consideration... I thus phrased it as "many Christians believe they are metaphorical children to an autocratic father in heaven" --- this is a statement that can be agreed upon whether one is a theist or an atheist or something in between.
Just to be clear on my position, as you note, I am an atheist, so when I say "God sees us as children" I mean if we suppose hypothetically that the Christian position is correct, then God sees us as children. We phrase it differently, but I think the meaning is the same here.
Indeed, there are implications to this belief as it relates to human rights... at least with respect to how those same Christians might understand them. Rightly or wrongly, children are typically viewed as irrational and ignorant compared to adults and thus incapable of forming rational and worthwhile opinions on matters... indeed, this is implicit in the UNCRC when it tramples on their right to freedom of thought, conscience and religion by subordinating it to their guardians who must "provide direction...in a manner consistent with the evolving capacities of the child". The gulf between humans and the omniscient deity that most Christians believe in is conceptually even wider... if this deity restricts or denies entirely the right to freedom of religion to humans, as you suggest is implied by your initial citation from within the Decalogue (more on that below), this is entirely consistent with how human rights documents treat children implicitly or explicitly. As such, your argument is compromised. While I can appreciate that you hold to an ideal in which children do have this right, that is not generally reflective of the world we are presently living in nor does it represent the majority position on children's rights as they have thus far been expressed through various rights documents.
I am still not clear, then, what the Christian position is.
Are you suggesting rights are relative? That is, a person only has to respect the rights of their peers, and not of their inferiors? Thus an adult can disregard the rights of a child; God can disregard the rights of an adult.
To me, that is antithetical to the whole concept of rights, which should in intrinsic. It is a short step from there to saying the ruling elite is not required to respect the rights of citizens; citizens are not expected to respect the rights of slaves.
With that ball in motion, I return, as promised, to the initial subject of the Torah text with which you began... the immediate context of "other gods" are those of the Canaanites, whom the redactors indict for practicing child sacrifice --- we agreed that this is a legitimate restriction on freedom of religion because it infringes on others' right to life. You thus widened the net to include the worship of ostensibly peaceful Hindu gods, yet does the Decalogue text really have these deities in mind or actually condemn their worship outside the community of Israel? The text arguably reflects a monolatry imposed by the Israelite deity on his people who agree to the terms of the covenant... only later, within a framework of monotheism, could its ideas be extrapolated to humanity as a whole --- and no doubt a large number of your interlocutors hold to this (mis)interpretation, along with the anachronistic concept of eternal suffering in hell, but I'm not convinced it is prudent to build scenarios based on readings that ignore the historical context of the biblical text, which is arguably more tolerant of other deities receiving worship than you allow.
My argument is with Christianity. My point is that there is a dichotomy between God's disregard for human rights, specifically with having those who fail to worship him suffer in hell for eternity, and the claim "God is love". Christianity is therefore inconsistent, and so can be rejected. Therefore what is important with regards the First Commandment is not how it was originally intended, but how it is understood by Christians today.
Certainly the author of the Torah text would not have believed anyone would suffer in hell for eternity. In its original context, it makes sense. This was part of the contract between Yahweh and the tribe assigned to him by El (I am not sure quite how old the text is; maybe not that old). Yahweh would look after the tribe, give them victory in battle, etc., but they had to keep up their side of the agreement, and not go worshipping other gods.