Yes, you explain it well. You say these egoistic and cosmic views are useful but fundamentally wrong. But they could be useful only if they were realistic enough for achieving certain purposes. So we're really agreeing but emphasizing different projects.

You emphasize Buddhist practice. I emphasize the limited reality of "suchness's" natural complexifications and emergent forms. You say those forms are fundamentally empty in that they have no eternal essence or endurance. But that's consistent with saying they're not entirely empty: they're temporarily real, and we have some limited power to arrange them while we can.

Suppose someone identifies with the oneness of everything and becomes unattached to her conception of her ego. Why should she be content with the infinitely shifting suchness? It's not exactly an uplifting picture for social creatures, since we learn that our preoccupations are ultimately futile. Isn't this, rather, a horrific vision of reality?

The oneness's infinity would amount to its indifference towards any of its mere hollow, easily replaceable forms. Shouldn't the enlightened person reflect that indifference, neutrality, and amorality? Whence, then, the emphasis on compassion? I don't see how compassion "naturally" follows from enlightenment. What I do see is the social utility of pretending that enlightened people tend to be compassionate.