1) They are different weapons. As far as I know, SWG's Nuclear Missile is identical to the Chinese Nuclear Missile. The Cruise Missile is its own weapon.
2) I don't understand what your asking. The USA Nuclear Missile and Cruise Missile Launchers look identical, nothing like the China Nuclear Missile Silo. You must mean the launchers look like the model for the Particle Cannon. Indeed, the circular segment is used for the launchers.
3) "Lazr_AmericaTankCrusader".