How so? If I have 2 travelers and 1 equipment ground in the romex wouldn't the ground work as a return
(is that the right word?) to cancel out the EMF? I have no problem using 14/3 just didn't want to if I don't need to. The ground would be connected to the neutral bar in the panel because that is where the neutral/ground bond will be made.
You stated that a hot & neutral are at each threeway and only the travelers go between the switches.
For that setup to turn a light on and off, the common of one threeway will be connected to a hot and the neutral will not connect to anything. Current from that hot goes through that threeway and down a traveler to the other (second) threeway where the common is connected to a switched leg going to the light (presumably in another 14/2). The neutral from the light connects to the neutral at this second threeway (note that the hot is not connected to anything). The current returns to the source along the neutral at the second switch.
In this setup, the only time the current, going in one direction in a cable is beside the same current returning inside the same cable, is in the switched leg between the second threeway and light.
Otherwise, the current is unbalanced and creating an un-canceled magnetic field.