I believe we can differentiate between medical procedures that are beneficial, or at least low-risk, and those that are not. There is no reason to force ourselves to forget the difference between circumcision, FGM and tattoos. A free nation need not be a willfully ignorant or thoughtless nation. Being free doesn't mean that we ignore our traditions or our culture. It doesn't mean that our government must see everything through some hyper-rationalist lens that discards anything it can't understand.
Now if tattoos were mandated by religious beliefs, maybe that should be legal. If they are just there for the parents' aesthetic tastes, not so much.
As for cosmetic surgery, how about dental braces? I guess Susie needs to be of age before she can get her teeth straightened?
So what you mean is that there's no outright right for parents to inflict what they want on children's bodies. That there should be laws deciding what is legal and what is not, based on, quote, "our traditions and our culture." I agree with you.
I do not mean in my argument that male circumcision necessarily should be banned. I am not of a set mind on that issue. All that I mean is that there's no specific, God-given, inherent right to choose whatever medical procedure you want for your child. There is a place for the State in this relationship because the child is a separate entity, with rights of his own.
As a libertarian, I believe a person owns
their own body and it should be their legal right to have whatever medical procedures they want to have, as long as they can pay for them or get someone to perform them of their own free will. But this isn't the case here.
As you've said, all medical procedures are not made equal. In my view, this is the exact room for local legilsatures - like the SF one - to intervene. No inhuman oppression has taken place.