Good question - and there is no one answer. Because it depends entirely on the question. Asking someone's opinion is fine - but many of the questions we get are not about seeking our opinion at all.
I'll try to break it down:
Questions about women's feelings and behaviours in straight relationships are generally OK. Though I don't include "Is my cock too small" / "she's had bigger" anxiety in that.
Questions about physical behaviour / characteristics can be fine - though I mean female behaviour and characterisitics. "Do women like a curved cock?" is most definitely a men's issue.
Questions about what women like are sometimes just a really transparent ploy of someone just fishing for jerk off material. "Duz u lyk it wen a guy jackhammar fux u 4 18 hours solid, babeeee!!" kinda thing.
Generally speaking it is fairly obvious if the person, male or female, has a genuine question. Of course, the Women's Issues forum was never intended to be the "Ask the Women!" agony aunt forum but it does seem to function at least partially in that way. And the questions that seem to be genuinely seeking to understand I try to answer if I think I can. The obvious masturbation questions and the just plain dumb stuff do annoy the crap out of me though.
Hey - at least the Rate my Cock threads seem to have all but vanished from here. I have no idea if some kindly mod is sneaking on here before me each day and moving them, or if my 'Your cock is not a Women's Issue' thread had the desired effect, or perhaps something else happened. But the forum is a better place for it.