1.Mobile exactly means, you can fire, pick up shop and change position.
2. It depends on which element is destroyed..Command truck or radar truck..yes. launcher, relay vehicle etc ..No.
3. Even if RAAD is fired at it maximum theoretical range of 350 Kms, it would still be inside S-400 range. Besides GPS or Tercom guided cruise missiles are not very effective against SAM batteries unless you know there exact co-ordinated..which is impossible to know..since it is not a fixed structure. Even if the missile battery moves 10 meters from its position the ALCM would be rendered useless.
4. One need a standoff ARM with 400 Km range to safely target such a SAM.
5. The worst part of Pakistan here is, all Pakistani airbases will be in S-400 range, As soon as in aircraft takes off , it can be targeted.