Is it allowed for me to donate a flat to each of my children except one considering that the tuition fees I paid for the latter`s university study are equal to the price of the flat? In other words, he has received his share and this is why I`m donating a flat to my other children?

Is it permissible to pay the expiation of an oath to a charitable party as it feeds the poor and needy such as Tkiyet Um Ali?

All perfect praise be to Allah, The Lord of The Worlds, and May His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions.

There is no harm on authorizing someone to handle the expiation of another to the poor and needy, since Shafiee's jurists stated that authorizing someone for the purpose of distributing Zakah, expiation and vow is permissible as stated in [Mughni Al-Muhtajj, vol.3 pp.237]. At last, the intention of the person who intends to authorize someone else suffices in this regard. And Allah Knows Best.

Is it permissible for a man to propose to a woman during her `Iddah(waiting period)?

It is impermissible to propose to a woman in her `Iddah, but there is no harm in making an implication to such an end in case she was observing it due to the death of her husband.

Is it permissible for me to name my daughter “Leen”?

“Leen” means “ease”, and there is no harm in giving your daughter that name.