The kicking foot method of determining stance is just a generalization, and in my opinion, a bad one. I think the slide technique is a better option for helping to determine stance. In general, if you try both stances one will feel way more natural, especially trying to skate around.
p.s. I ride goofy and kick with my right foot, along with many, many other riders
+1 I kick with right and ride goofy as well
try a skateboard and see what is natural