-Rising and sinking from what reference point?

As polarities, they reference each other. But the reference point that's significant here is the reference point of the learner -- the one making use of the symbol. For someone learning about yin and yang, learning their properties is significant. As much as people may like to couch Taoism in New-Agey 'anything goes' terms, that's more about their own vagueness, and far from the profound teaching of Taoism.

-If the transmission of the symbol's meaning is really what's important then any picture that allows you to feel yin and yang combine in any chakra (or "point" in space) would be the correct representation, wouldn't you agree?!

No, I don't agree at all! Why bring 'chakra' into it? Why make "feeling yin and yang combine" rather than perceive things as they are, whether separate or combined? Why make "point in space"?

If you want to flip the symbol around and change it according to your ideas, that's fine; it's no big deal. But it will be according to your ideas and your perspective. Let's not be so arrogant as to call it "the correct way" just because it suits our preference. That constitutes a dumbing-down of teachings passed on by great masters, to say that however we understand it at the moment is right, and there's no significance to the teaching passed down other than how it suits our momentary whim.

The online community in particular is vulnerable to 'study by consensus', wherein what is palatable to the majority is passed on as the legitimate teaching. Folks think that freedom means they get to think and do whatever they want: no need to adapt to a profound teaching, no need to ever be without opinion, no need to ever change one's view. That's not freedom.

People can have their opinions and perspectives; I'm just sharing what has been passed down from teachers far more experienced and insightful than you and me.