Is it permissible for a wife to conceal from her husband the permissibility of feeding in lieu of fasting for the expiation of Dhihar, especially since he intended to feed sixty needy persons after completing his fast?

A severe warning has been issued against concealing knowledge, except in cases where not issuing a fatwa is permissible if it leads to harm. For instance, the Messenger of Allah, peace and blessings be upon him, forbade Mu'adh ibn Jabal from informing people of the hadith, "Whoever testifies that there is no god but Allah..." In the case of the questioner, there is no harm in not informing her husband of the ruling until he completes his fasting. If he is able to fast, then he is not permitted to feed the poor.

Regarding the second question, whoever does not find a slave to free and fasts for two consecutive months has fulfilled his obligation. It is not appropriate to feed sixty poor people after that, as it deviates from the expiation for ẓihār. He may give charity to the poor and needy in any way he deems appropriate. It is not permissible for him to perform two expiations for a single ẓihār.

As for the third question, embracing one's wife and kissing her before completing the expiation is not permissible. However, the continuity of the fasting is not broken unless something occurs that invalidates the fast.