No - I didn't suggest 'just because', and Libertarians reject norms not 'on a specific basis' - they reject the nature of the limiting impetus on their expression.
Norms are by by default bad and can only be justified in a narrow sense.
Critically, there is no moral impetus but the expression of one self. There is no 'greater good', 'community good', or even 'greater morality' beyond selfish desire.
Rules and norms are only seen through that lens.
Yes - 'rights' can be viewed as norms under most libertarian thought but only to the extent it supposedly protects individual will.
These ideas are useful tool, especially when concerned with materially oppressive systems (such as those Ayn Rand lived through in Soviet Union) but morally and practically bereft or at least lacking outside of more authoritarian systems.
Says who? The non-aggression principle is a limit on "expression"--you can't "express" something that violates someone else's rights.
I think the correct word to describe what you're actually thinking of is "libertine", not "libertarian".
Is hardly an example of what you're describing. She explicitly supported property rights and the non-aggression principle.
It's interesting, though, that she refused to identify herself as a libertarian because she saw those who did as anarchists. So she apparently had the same kind of misconception about libertarianism that you do.