If you can measure the resistance at more than one point on the surface
of the rod, does this imply that the rod surface is conductive
everywhere along its length?

If you could attach the wire to the rod so that it touches everywhere
along the length, then the current would divide between the rod and the
wire according to their respective resistance per length (most of the
current would flow in the wire) and the currents induced in the pole
would be in phase with the currents induced in the wire.

I think it would help to have the wire attached at least at the bottom
of the pole and the top of the pole.

If you attach the wire only at the top and ground the bottom of the
pole, you make a rather lossy folded monopole. If you attach the wire
at both the top and bottom of the pole and insulate the whole structure
from ground, it's more like a cage monopople with one lossy wire and
one good wire.

Dan