You're trying to perversely get to the logic of the pro-life position from the foundational assumptions of the pro-choice movement. If that could be done there would be no debate.

So I am afraid yours is a bad-faith position.

A pro-lifer would consistently argue that he/she is merely arguing for a living being who cannot argue for himself/herself. He/she would further argue that a woman's unborn child is NOT a part of the woman's body, and therefore not hers to decide what to do with. Anymore than your dog is "yours" to be cruel to, without regard to what the SPCA has to say.

You may not agree with pro-lifers but reducing their position to an idiotic strawman obscures the fact that there is genuinely a difficult moral issue here. It is fundamentally disrespectful.

I am personally undecided on the issue because I think there are some true unknowns here. The best we can do is try and be kind to all concerned in the matter. And yes, whether you agree or not, apparently "unrelated" people DO have moral locus standi here. To paraphrase John Donne, no woman is an island.