I don't see any of those nightmare scenarios happening. But what her "hanging on" does do is reinforce the false premise that there is some duty to preserve status quo ante of the balance or makeup of the SCOTUS. That each nominee should mirror the philosophy of his or her predecessor.
Lots of that sort of talk going on, and will continue. Schumer said outright, "Alito is not in the mold of O'Connor," and uses that as a springboard for his preliminary objection. "A divider, not a uniter" is the same sentiment in less personal terms.
I don't see any of these nightmare scenerios with O'Conner.
She has always seemed honorable.
My real fear is for the future, and the precident this sets, and what may happen if someone more prone to write law from the bench were to do one of these "contingent" retirements.