Is a woman who has had her marriage contract solemnized, then divorced before consummation, obligated to observe the waiting period ('iddah)? And is her marriage to another man before the 'iddah ends considered void? And do legal rulings apply to a void marriage?

A woman who is divorced before consummation has no waiting period (iddah), by scholarly consensus, due to Allah's saying: "O you who have believed, when you marry believing women and then divorce them before you have touched them, then there is not for you any waiting period to count concerning them." Therefore, her marriage immediately after her divorce is valid, and the divorce issued by the second husband is binding. It is not permissible to explicitly propose to a woman in her revocable waiting period, but it is permissible to allude to it.