A lot of libertarians do support it because they support liberty & free will. Most politicians who openly support marijuana legalization are either libertarian or liberal.
Libertarians believe you can't infringe on someone's rights. Therefore libertarians support it.
Libertarians believe the government should not be telling people whom they can and cannot marry.
Generally, yes. Libertarians, by definition, oppose government interference with people's lives and therefore do not support the government placing arbitrary limitations on families.
Her activism in support of birth control was the reason she was controversial.
Probably yes, but few. They will probably be Left-winged. There probably are some, but they would be EXTREMELY few (to the best of my knowledge). Actually, the Libertarian Party officially supports the right to own firearms, but they also support abortion, homosexual marriage, marajuana, and just about everything else. Many conservatives (including me) who are against gun control shy away from the Libertarians for this reason.
Libertarians generally support limited government intervention, including law enforcement. However, they may advocate for police reform to ensure individual rights and limit government overreach.
Laissez faire because abortion is a sensitive issue, which by the way most libertarians are pro choice.
No
Prenatal vitamins are to make sure you have enough vitamins and minerals to support a pregnancy. Birth control is to prevent pregnancy. They have different purposes. Birth control does not support a pregnancy, and prenatal vitamins do not prevent pregnancy.
There is no scientific evidence to support the claim that birth control is intentionally being added to the water supply.
There is a huge difference between the views of totalitarians and libertarians. The former believes that the government should control almost every aspect of a nation. On the other hand, libertarians believe that government should be small and not intrude upon the peoples rights.