We have unlimited Sprint, which if IIRC, is no longer available, Verizon MAY be the same.
Double check that on off thing with the Air card, friend of ours, OntMont, turns his on and off, but believe his is a air card, not a tethered phone. I thought he had Verizon, but, you know, ole leaky memory issues.
That said, THINGS change all the time, ya all know that!