Thank you for taking the time to understand my comment in its best interpretation!

Taking your reply in reverse order:

> Am I actually a moral absolutist, but misunderstanding
> the terminology?

I could be misunderstanding what you mean by "absolutist", because the terms I'm used to seeing in this context are Objective Morality vs. Subjective Morality. I'm assuming you're arguing for Subjective Morality (aka, moral relativism, aka "morality is a human invention, we decide what's right and wrong for ourselves"). If by Moral Absolutist you instead mean "there's a finite list of rules and regulations by which all humanity in all situations at all times should be living by," then I'm not arguing for that at all. So, I'm assuming you don't mean that, and that we're actually talking about Objective vs. Subjective Morality when we talk about relativism/absolutism.

I think as soon as you use terms like "should", "ought to", "right", "wrong", "good", "bad", and "evil" that you're making an objective statement about an ideal state to which you think the world should conform, ought to conform, etc. From a theistic point of view, those words make sense, but from an atheistic point of view, every time you use one of those words to refer to someone else's behavior, I'm going to ask, "Why?". Basically, if you try to effect any moral change at all in anyone, you've proven that you actually think there is at least one thing which you consider to be "right" for the other person to do, regardless of what they think about it.

> I do think that everyone should behave with empathy
> because all humans have an equal capacity to suffer,
> and from that conclusion you get obvious things like
> "rape is bad", "murder is bad",

You may think it's bad, but you haven't really got a strong argument there for why it's true that murder is bad at all. You may not like murder, but why should the murderer care what your preferences are at all?

Here's what I think is a stronger, more formalized version of your argument:

Premise #1: All humans have an equal capacity to suffer.

Premise #2: Suffering is a specific electrochemical impulse in a human's brain.

Premise #3: Every human dislikes the "Suffering Impulse"

Premise #4: Human beings *ought* to reciprocate their dislikes.

Conclusion: Therefore, everyone *should* behave with empathy.

Note that even in that argument, I couldn't even come up with a good premise for #4 that didn't use the word "ought" (and again, I'm trying to come up with a good atheistic argument for why anyone should behave in any particular way at all). And you need #4 for the argument so that the conclusion will follow from the premises.

> I feel that a moral hierarchy exists, but it does not
> exist independently of the (collective) human mind.

To see where this idea logically leads, I'd encourage you to read some articles by John Gray[0]. He's an atheist who writes a great deal about the implications of atheist worldviews on morality. He's a clear thinker, and not afraid to ruffle feathers.

Also, I highly recommend that atheists read Frederich Nietzsche's "Parable of the Madman"[1]. It's another take on the moral implications of atheism.

[0]: https://www.theguardian.com/profile/johngray

[1]: http://sourcebooks.fordham.edu/mod/nietzsche-madman.asp