Update on my situation: The order of the universe has been restored.
USAA funded on schedule (barely) and covered about $500 in non-allowables that were charged by the escrow company (e.g. “loan tie-in fee,” the “key grip” of closing costs). I still say their communication could be better (serious C4I problems) but at least I have keys.
OTOH, The Very Big Impersonal Bank failed to come through, miserably. The “personal banker” basically told me to shove off when I called him the next morning, and the funds verification letter came four days after closing. Good thing I didn’t need it.