Manipulation Quotes in Eclipse

What Jacob really means to say with his question is: "I need you as a friend, don't you need me?" What does his roundabout way say about the workings of manipulation?

Jacob use his own pain to guilt-trip Bella into finding a way to see him again against Edward's wishes. On the other hand, he is in pain, so is his behavior unfair or not?

Apparently presents are a good way to manipulate people. Are all presents manipulative?