"IIRC, Parachinar is the gateway to the Khyber Pass and to Kabul, virtually autonomous from Pakistani
authority. "
That sounds more like Peshawar. Parachinar is west and south of there, in the "parrot's beak" region opposite Khost and the Paktia province.
You are correct about their autonomy. Both are gateways into Afghanistan, and both have been traditionally subject to little government oversight. There have been indications that recently the Parachinar area has been sanitized by Pak troops, without a fight.
Mea culpa.