So just started Pokemon platinum and took a good look onto luxray's egg move (also shinx/luxio) and thought to myself: can I breed luxio with shinx? the egg moves are actually decent. I don't want my luxio to be worthless and catch 2 other shinx, because by then I will just ohko them.
Yes, any Pokémon within the same egg group can breed with one another. Shinx and Luxio are both in the field group. They also have to be opposite genders. Ditto can breed with any Pokemon excluding Pokemon with no egg group.
Yes. All Pokemon of the same egg group can breed together, which usually means the evolution line of a Pokemon can breed together.