Najafi Q&A: Divorce Formula

Is the presence of the two divorce witnesses required in the session of pronouncement, or is it sufficient for them both to hear the voice of the one pronouncing the divorce through the phone or similar means?

In divorce, is it necessary to pronounce or write the statement three times, or is pronouncing the divorce formula once sufficient?

A man divorced his wife for the first time when he was not consuming alcohol. After a few months, he took her back. Several years later, he divorced her again but reconciled with her after a few days. However, during this period, he became almost addicted to alcohol, may Allah protect us. Two days ago, he divorced her for the third time. The question is: In the last two divorces, he approached the registrar while intoxicated, as he was nearly addicted. Is the divorce valid? And can he take his wife back after the last divorce?

A married woman, who had a dispute with her husband, left and stayed at her father's house for two years. Now her husband is planning to divorce her. Is it a condition for the divorce that she should be in a state of purity (not menstruating), and he actually did not approached her for two years?