Jewish males can still have their private parts circumcised when they become adult as it was supposed to be the case, a rite of passage for getting into the adult world.
Most of your rebuttal is centered around a "slippery-slope" argument and it is not convincing enough.
As an orthodox Jew, I can tell you that failure to circumcize your son at 8 days old (outside of extenuating circumstances, e.g. medical issues) is one of the worst sins you could commit.
Furthermore, you would be ostracized from the community, and your child will suffer socially, and emotionally.
Once the child turns 13 he is responsible to ensure that he it's circumcised, and considering that he most likely will not have abandoned his religion by 13 he will go through with it. So now there's physical pain as well.
And if a government would ban circumcision, I'd be willing to bet that all Orthodox Jews would leave. And if the government prevented that (which has certainly happened before), then it is well documented that many Jews are ready to give up their lives in order to circumcise their sons.
Update: only my first comment was theological; the rest were socio-physical
> by 13 he will go through with it. So now there's physical pain as well.
1. One example is Ch 4 and 5 of http://www.circumcision.org/cht.htm
Slippery slope argument says that "we shouldn't do X (even though X is inherently okay) because it might lead yet another set of actions – Y – which is a negative". I'm not saying that at all. Banning circumcision will lead to significant identity issues as a direct consequence, not as a result of some other intermediate effect that obtains as a result of the ban.
It was like "Hey boy, you've hit puberty and become a man now. Let's do this small rite of passage and cut that foreskin off your dick so you could join the rest of the tribe of grown up men"