Please help me...

Okay admittedly I'm a noob, playing on an old world where I built a castle, castles so big mobs spawn, I've looked up the various ways to stop this, they all suck (for me)

I want to use the I'm settings cheat "mob greifing" and turn it off but first I have some questions

  1. Does this stop mobs fighting you
  2. Does this stop villagers becoming zombies (I know there's a cure)
  3. What else does it cover

P.S the "mob spawning" option, I'm assuming it stops them all together, including mob spawners, in dungeons/caves, etc