Thanks four your answers.

I was forgetting you normally use coax in a unbalanced configuration
where the braid is supposed to be at 0 voltage so only currents matter.

Would all this still hold if you used the coax as a _balanced_
transmission line? (unusual but -I think- possible). In this case
wouldn't voltages develop on the braid that could capacitively couple to
other conductors?

(assuming perfect solid shield, ...)

--
Toni