Ok, Scummy, I am constantly suprised when the 'socialisation' issue comes up. There is far more opportunity for mixing with a much wider group of people. In school, you sit in a class with 29 other kids with whom you may have nothing in comon, except age. At primary level you have one teacher. I cannot understand this being considered a social situation - I remember countless times being told off for talking. In HE, yes there is one 'teacher', but the problems which usually arise in school with just one teacher is a personality clash one, or a lack of understanding one - and that doesn't apply with a parent.
In the course of a HE week, you (have the potential to) meet a huge range of people. Most children who are HE'd go to HE groups (which often offer a very diverse range of activitis and therefore a diverse range of people), 'after school' type activities, many do voluntary work of some kind, and in addition to that there are the people you meet just in everyday life - the delivery man who comes to the door; someone who comes to fit the washing machine; neighbours; shop staff; bus drivers; librarians; museum attendants; tutors etc, etc, etc. And without the adult/child devision that comes with shcool (ie I'm the adult = superior, you're the child = you do what I say) they are able to form relationships on a far more balanced, equal basis, with a far more diverse selection of people. Just because there is only one person undertaking the majority of the 'teaching' (which isn't always the case) that doesn't mean that that person is the only influence.
I accept that in some cases HE is a way of preventing children experiencing different viewpoints, but I think those people who do it for sinister reasons are a tiny minority. Many people do HE for religious reasons, but not to indocrinate their children. Some christians, for example what their faith to be the basis for their child's learning, but that doesn't mean it is exclusive. I am not religious, but I can understand that to some degree - the 'religious education' I recieved at school was appalling. I seem to remember colouring in cartoons of bible stories and watching the odd video, and that was about the extent of it. If your faith is important to you, then I can understand wanting it to play a slightly more significant role.
For myself, I am wanted art to form the basis of my children's learning, and I also wanted issues which come under the heading of 'citizenship' to take more priority. Environmental and human/animal rights issues are very important to me and I wanted them to take more precidence. This was not a major factor in deciding to HE, but to some it is.
Your second point (what, with all that waffle, I have only covered one of your points!!!)I think is pretty much the point Dadslib was making about the superiority complex! I don't think that I alone can handle my child, but I do feel that I can handle him best. I can offer him learning that he will enjoy, not come to resent. I know his strengths, and weaknesses, the things he likes doing, the things he doesn't. If learning can be adapted to make it fun then it sets up a lifelong pleasure in learning. To me, that is a good thing. In school, forced to learn what they are told, to start where and when the teacher dictates, to stop (even if you are in the middle of something) when the lesson ends, is to disrupt the learning process. It makes it disjointed, something you do because you have to. For my children, learning, like play, is something they can do all day. Their time isn't divided into school hours and home time, their activities aren't divided into subjects with distinctions between whether what they're doing is maths, or history or geoghraphy or whatever. They are learning all the time, and it's fun, and enjoyable.
HE isn't a cop-out, any more than private schools, for example. It's a valid educational decision. And while I agree that we should be lobbying for a good educational system all round, that is a long way off, and I am not prepared to sacrifice my children's education in the meantime.