I think the difference between stealing and tracing is the context behind why you did it.
If you are using an exact copy of an already existing art work and calling it yours, that's stealing. That's lazy since you are not learning your own technique and just creating a carbon copy of someone else's work.
But tracing a hand position, a body twisting in a weird way or some extreme perspective shot is different. If you using tracing as a learning tool, then it doesn't become a bad thing. Yeah you might still use a traced thing in your artwork/comic but you are not copying someones work so to say.
I think the easiest way to view it is that if you copy someones character or something they have made up, that's wrong and can be classed as stealing.
A body position or hand gesture isn't someone's original work, in the sense of a human body doing natural movements/in natural positions. We all have bodies that can do the same thing, so it's not a copyrighted thing that can never be replicated again. Still try and learn to be able to create these positions yourself, but you shouldn't feel bad if you are copying anatomy.
I myself try to draw things from just looking at a reference if I am unsure, but occasionally that doesn't work. So I might trace over a hand or body as kind of a sketchy stick figure to then go over it and flesh it out in my own style. This way, while you are copying/tracing something, its more of the skeleton you are coping instead of the entire artwork line for line.
There is no reason why you should feel guilty, since you are (at least I hope) using tracing as a way to learn, not profit off someone else's skill.