Yes, they are based off your physical crit rate. Also, the fact that the damage is based off of PAtk is maybe not clear enough. At least it wasn't for me. PAtk doesn't just cut through the target's defense like it does for most physical skills. It contributes directly to the damage of the skill (equivalent to how PDmg works) at a percentage of your PAtk. Obviously, your PDmg also contributes. Hope that helps.
