I think the problem with pants is that it blurs the lines betweens the sexes - that doesn't necessarily make it sinful. It becomes sinful for a woman to wear pants when they are immodest, just like it's sinful to be wearing a tight or mini-skirt. It's definitely better for a woman to wear skirts, but I don't have a problem with a woman wearing modest pants for convenience sake occasionally(for example, gardening, horse-back riding, hiking, sledding, etc...) Perhaps these are all things that one would argue are "inappropriate for a woman to be doing," or that "could just as easily be done in a skirt." As to that, we can disagree on what are appropriate activities for a woman; some men are more chauvanistic than others and some women are more feminist. And they could be done in a skirt, but it can be a real pain in the a**, like I said, for convenience sake. But, no, I don't think pants on women, in and of themselves are evil.
And it wouldn't take much to stand out in Las Vegas - wearing knee length skirts all the time would set one apart enough - but take that same person and put them in St. Mary's and she would be borderline liberal - it's all a matter of what is perceived as socially acceptable.
I don't think it is right to dress like a slut or a factory worker and, like Fr. Angles, I don't think it is right to dress like Little House on the Prairie either. It draws the kind of attention that says, "Look at me, I'm holy and weird, and extreme! I'm in a weird cult!" And who wants to convert to that? Just like falling in love, there has to be some kind of initial attraction to the Faith; "weird" isn't exactly a turn on.