I like separatist feminist theory and remember getting all a fluster about it in my younger days. As I've aged gracefully Its been shelved as the "good theory, but not so great in practice". I'll try to put my thoughts into a coherent sequence.
Starting with the premise that if the women separated themselves then the men would realise what women contribute. Well, possibly. Or perhaps they would adapt to surviving without the contribution of women and therefore devalue it more. From my point of view there's more value in changing male perception of gender roles by challenging them openly and directly. I am not sure how that challenge could take place if they are separate.
Moving onto sex and children. The creation of babies (unless you are going IVF) is always going to involve penetration in one form or another. If you are against penetration of any reasons then the questions about children are moot. `
However the point about male children is a good one. Taking into consideration that most children in western society live with their parents until around 18 years or older, at what point in a separatist commune would a male child be welcome?
I am absolutely not suggesting that a mother wouldn't care as much for a son, or not love or take care of them in the same way, but it is an interesting point. Girls, I presume could stay on in the commune and learn the values of that group, but when would a boy stop being a child that can function as part of the commune and become part of the patriarchy? Puberty? 16? 18?
I have to admit that living in a female society is very attractive but I don't necessarily think that its a good way to challenge the patriarchy. It would remove me from it (well if I could live that way without having to interact with the outside world), but challenge? I'm not so sure.