Hi,
The answer to the second question is NO.
The speed of light in a medium like air or glass is governed by its refractive index see
http://en.wikipedia.org/wiki/Speed_of_light. For example the speed of light in glass is less than the speed of light in air which is less than the speed of light in a vacume.
I dont believe this applies to radio waves in the same way so i would say radio waves in the atmosphere are faster than light waves.
Regardless, this still means that the speed of a particlar light beam is the same for all observers.
Cheers
Paul