for the diagram make sure no K+ pluses are touching together and make sure no Cl- are touching together. For the question, you need to mention how electrons are now delocalised, if electrons can move or flow they can create a current.(basically conduct electricity).
No, each K atom must join to 3 other Cl atoms, and each Cl atom joins to 3 K atoms. That way no two Cl atoms are touching & no two K atoms are touching, because two potassium atoms have the same charge so they can’t be joined by electrostatic forces of attraction. There shouldn’t be any lines between them (the line represents a bond), as they don’t form bonds. Hope it makes sense.
For the diagram you have to make sure that an atom is not connected to the same atom but to another one. So the K+ should be connected to the Cl- and vice verca.