What public schools, in US cities, are teaching christian mythology as though it were science? That is a rare problem and I really rather doubt that many people are homeschooling their children because their public schools are insufficiently secular. If you have really found yourself in that sort of situation, there are plenty of organizations that would
love to get involved there...
Your school doesn't have the money for fancy microscopes? Welcome to society; get involved with it and fix it.
> Does my exposure
I thought I was clear: exposure to religion in an education is not what concerns me (unless, of course, it is in a public school). The RCC, for all of its numerous faults, has their schools in developed countries teaching proper science, not religion in place of science (for the most part), and not in the same class. They are pretty damn low on my list of concerns.
My concern is with adults deciding to swap out science lessons with religion lessons. This is what the majority of homeschoolers do, and this is what many protestant religious schools do.
> If I'm doing something extreme or harmful to my child
Denying your child access to a basic science education is exactly that. Children have a right to receive and education and parents have absolutely no right to deprive 'their' children of that.
Explanation by example: You want to send your kid to Catholic School where he can learn proper biology and latin prayers or whatever shit? Cool, knock yourself out. You want to send your kid to public school where he can learn biology, then teach him that Jesus rode dinosaurs when he comes home at the end of the day? Cool, knock yourself out. You want to keep your kids out of schools that teach biology and instead only expose your child to Dino-Cowboy Jesus theory? Then you should have your children taken away from you, as you are clearly incapable of raising them.