The paralysis is their ONLY form of basic offense. I may have been influenced by the ghoul, which is DC 12, but gets three chances to pull it off in a full attack, plus is dealing hp damage. And yes, I know that from a pure design standpoint ghouls are a bit of a problematic creature.
The Strangle requires failing a LOT of saves in a row to actually do anything. I might reduce the magnitude of the static bonus a bit though. I SHOULD at least consider changing it to use the strength modifier rather than the score and maybe bump up the strength a bit to compensate.