As far as abortion, I don't believe libertarianism can be defined on either side of this issue. There are many libertarians on both sides of this issue, and I believe libertarianism fits either side of this issue. As libertarianism isn't just pure freedom, it doesn't allow you to murder another human being other than self defense.
So the point would be at what point are you murdering another human being, some believe birth, some conception, and some in between. My personal belief is about the second trimester, other than risk of life to the mother, so that puts me somewhere in between. But any of them fit under libertarianism as its definitions are not able to define this issue.