Nope. We need a lot more conflict in the world than we have right now for a world war.
Only if Mrs Didge finds out that I broke her favourite cup. :(
Yep, it's scheduled to start on July 17th this year.
No.
No, never happen ! No one is strong enough militarily to start a major war, let alone a World war.
If by "world war" you mean a war involving numerous nations from around the globe (as opposed to just in a limited region) ... We have already had WW3. And WW4. And WW5. We're probably around WW10 or so, now.