1) If the position gives the opportunity
2) No, you don't calculate to get the initiative. You should learn positional concepts. If you can, then you are having the initiative.
3) If their initiative is forced, then you cannot turn it without a mistake by them. However, I advise you to always check in-between moves, and counterattacks
4) Practically impossible. If you want to avoid counterplay, you must have a considerable amount of space advantage.
Initiative is a powerful thing.If the opposing player has hanging pieces or pawns it can decide the game for you.My questions are
1) How initiative develops?
2) Can you see 5 10 moves ahead and see an initiative ?
3) How to turn your opponents initiative in your favour?
and lastly
How to avoid giving initiative?