Is a divorce valid if the husband says to his wife four times, "I divorce" (meaning: I divorce), with the intention of annoying her, not of divorcing her? And is the fatwa that it is a kinayah (an ambiguous statement) correct?

The phrase mentioned is not explicit in effecting divorce, and the husband did not intend to effect it with it, so no divorce occurs thereby. The mentioned formulation is in the present tense, so no divorce occurs by it without intention, even if the husband attributed it to his wife. Therefore, no divorce occurred by what was uttered by the husband, as long as he did not intend to effect divorce.