I am an ENFP and I would say a strong NO to all 3 questions. It simply goes against my values and sense of commitment when I'm in an exclusive relationship. If I'm unhappy in a relationship I will first focus on addressing that fact within the relationship - often trying too hard I am told - but at least that honours my sense of integrity and commitment.

It blows me away when other people line up the next person when they're still in an exclusive romantic relationship. This has happened to me and I still don't understand why the person simply can't say that their feelings have changed.