it is scientifically proven that from the moment of conception the baby and the mother are two separate bodies.

According to who and with what criteria? At the moment of conception, the baby is not even a "body" at all in the first place, so I highly doubt that any evidence supports the choice of wording you used of "separate bodies". If you had said that they were both "living things" or "separate organisms", then obviously that would be correct, since both you and the growing fetus are clearly two separate organisms made up of living cells, but "separate bodies at conception" sounds like an odd misunderstanding of human development.

More importantly, the fact that the mother and the fetus are two separate organisms actually SUPPORTS my argument that abortion is justified. In fact, nowhere in my argument did I suggest that the mother and the baby are the same person, because I do not believe that is true, nor would this specific argument of mine make sense if they were. The reason abortion is justified is because no one has the right to use another person's body without their constant consent to do so, and therefore BECAUSE the mother and the baby are two separate people subsequently means that the baby does NOT have the right to use its mother's body without her consent. Using someone else's body without their consent means that you are violating that person's bodily autonomy, therefore they have the right to take whatever action necessary to stop you from continuing to use their body, which, in this case, includes an abortion.

I agree that no one should use your body without your consent, but I also agree that no one has a right to kill another human being.

I also agree that no one should simply have "the right to kill someone else"; that is why it is exclusively a conditional permission granted to you in response to a violation of you or other rights. You cannot simply kill someone just because you want to, nor should you have the right to, but what you do, and SHOULD, have the right to is defending yourself or others from those who violate you or others, respectively. Just as you do not have the right to physically harm anyone, you DO have the right to prevent yourself from continuing to be harmed by someone, of which inflicting harm yourself is permitted. If someone is violating you, you have the right to stop them from doing so, by any means necessary. Without that right to do so, what exactly are people expected to do when someone is violating them? Stand there and let them? If someone pulls a gun on you, then you have the right to shoot back, and are protected in doing so, even if they die...that is not "the right to kill", that is "the right to protect yourself against violators".

and the right to life is always more important because if you're dead you cannot enjoy any other right.

Sure, but YOUR right to life does not come before OTHER peoples' rights. YOUR right to life may be the most important right that YOU have, but it does not take precedent over any of the rights of OTHERS. That is why, if you are dying and need a kidney, you would still NOT have the right to violate another person's right to bodily autonomy by taking their kidney, even though they wouldn't die to do so. The right to bodily autonomy of a healthy person with two kidneys comes BEFORE your right to life, as they have the right to let you die by denying you their kidney. In this sense, other peoples' rights DO take precedence over YOUR right to life, which is what I mean by "your right to life is not the most important". YOUR right to life is most important to you, but any of MY rights cannot be overruled by YOUR right to live. Hopefully that clarified this.

In order to secure human rights you must necessarily violate other rights.

I feel I should reiterate, since you consistently seem to use terms like "human rights" and "natural rights" as separate from just "rights": all rights are made up. We made up the concept of rights and we, as a society, decide what rights we will or will not have. There are no objective rights, so your insistence on distinguishing between "human/natural rights", that you agree with, vs "delusional rights", which you don't agree with, is silly and unfounded on anything but your own personal beliefs on what should or should not be rights. This is all subjective...

For example, if humans have a right to housing/shelter, food/water, government must necessarily tax other human beings in order to guarantee these delusional "rights," and taxing involves taking one's money without consent, thus violating the right to private property.

See, this is why it is subjective. You are basing this argument on the premise that only the rights you agree with should exist, which I obviously disagree with. For example, I do not view taxation as an inherent violation of private property, because we have differing ideas of what "private property" entails. For example, I view taxation on goods and resources as merely a fee for maintaining society, the one which we all live in and benefit from. However, I do agree that taxation on personal income is unjust, as your income is the product of your own labor, therefore it would be unjust for another individual to take any part of the product of your own labor...although I use that reasoning in both government AND business, whereas you only use it in regards to government.

Finally, if you agree with my last point that government creates hierarchy, why do you believe in social welfare programs, which must necessarily be supplied by the government? If you were truly an anarchist, or something along those lines, you'd be totally opposed to that.

As I previously explained, government does not inherently create hierarchy, but our current government is absolutely hierarchical. Again, you have a misunderstanding of what "a government" is, as you seem to be under the impression that this is the only way governments can be structured, which is obviously untrue. A government is simply whatever means of decision-making a society utilizes. A government can be hierarchical, like nearly all current governments are, but they can also be non-hierarchical, like a direct democracy. I only support non-hierarchical systems, because that is fundamentally what Anarchism is. Anarchism, as an ideology, is not simply "anti-government", it is anti-hierarchy. I believe the only good governments are those that are non-hierarchical, which we don't currently have, but we should. And not just governmental hierarchy, I am against ANY structural hierarchy, including economic hierarchy, social hierarchy, etc. That seems to be a fundamental difference between us...