Wonderful questions!
If a parent is completely informed about all the risks that circumcision entails to their infant son, and still chooses to have them circ'd, does that make it ok?
I believe that the vast majority of people who are TRULY informed about the functions of the foreskin, the insignificance of the medical benefits (and ways that those benefits can be achieved without surgery), how the operation is performed, and the short-term and long-term risks of the operation will decide not to do it. However, if parents ARE fully informed and choose to do it anyway, at least they will hopefully do so without regret.
However, taking the choice away from the only person who will be affected by the decision still feels wrong to me.
If not, how is circumcision different than other parental decisions (ie. breastfeeding/formula, vaccinations, face down/face up sleeping, co-sleeping, etc) where one or more options carry risk to the infant/child yet parental choice is more readily recognized? In your opinion, why should parental choice not be recognized in regards to circumcision?
Every one of the examples you gave represents a choice that HAS to be made in infancy. A baby has to eat; a baby has to sleep; for most vaccines to be effective, they have to be given at certain times. Circumcision does not HAVE to be done in infancy; it can be done at any time in a man's life, if he so chooses. Even if a parent feels their child MUST be circumcised, it does not have to be done before he leaves the hospital - it can wait until breastfeeding has been established, the baby is bigger and better able to tolerate both the pain meds and the trauma of surgery, it can be determined whether he has any medical condition contraindicating surgery, and when his penis is bigger, reducing the margin for error.
If yes to the first question, how does being informed about the risks mitigate the actual risks to the child?
I didn't exactly answer yes, but I do think that if a parent fully understands the operation and the possible complications, they will be better able to deal with those complications. For example, there have been cases in the last few years of babies that have bled to death following their circumcisions. Parents who understand how much blood loss is too much might get their child in for treatment sooner. Parents who understand that adhesions are a common complication of circumcision, and who are taught to leave them alone, will not cause more pain and damage to the boy by ripping adhesions apart (or letting a doctor do it!) Parents who understand that many circumcisions today leave a fair amount of foreskin (to allow room for later growth) will not be alarmed if their son's remaining foreskin covers some of all of his glans. I've read many parents' complaints that their child "doesn't even look circumcised", and they wonder if they should have more cut off. A few years ago there was a woman on a circumcision debate board who was not happy with the way her son's circumcision looked, so she had it redone - not once, but twice! By the time he was 2 (? I can't remember exactly how old he was), he was crying every time he got an erection, because so much foreskin had been cut off that his penile skin was pulled tight. He ended up having reconstructive surgery (at least one, possible two operations? Someone else will remember better than me).
So yes, being informed can definitely reduce some of the risks - though things like infection, meatal stenosis, and "slip of the knife" risks wouldn't change.