I enjoyed your analysis. The only addition I would make is that Salem’s dip in the Grimm pool did change her at a fundamental level and, supposedly, gave her a taste for destruction. So, she is driven by a primarl, external force as well as her internal psychological problems. This is why I think that her grand plan is to bring the gods back to Remnant by collecting all the relics, making them judge the world, and then watch them destroy it – and her too, since as long as the world exists she will walk it. So, her plan is a final effort at suicide which also satisfies her desire for destruction.