Newbie question: How do pots limit current?
A pot doesn't break KCL or KVL, and as you say it's just a variable resistor.  Usually it controls current by converting a voltage on the pot to a current.  That's just Ohm's law-  The current is the voltage across the resistance divided by the (variable) resistance.

There's no law that says a series circuit has a constant current, only that elements in series carry the same current.