It is impermissible to pay the Zakah for settling the debt of the deceased since Zakah is paid to eligible recipients who are alive. As for the debts of the deceased, they are to be settled from the estate before dividing it amongst the heirs, but if the deceased didn`t leave an estate, then it is desirable for his/her heirs to settle those debts if they can afford them.

What is the ruling on having brotherly ties between a strange man and a strange woman, and is the former considered a Mahram(unmarriageable) to the latter?

Such a relation between a strange man and a strange woman is forbidden in Islam because it involves forbidding what Allah has allowed by marriage, and allowing what Allah has forbidden such as looking and the like. Such a relation doesn`t render any act lawful between them, thus they are forbidden to look at each other, have a Khulwah(seclusion), and travel together.

What is the ruling on a person who isn`t able to fast due to old age, or an incurable disease ?

Paying the ransom is due on such a person, and that is giving a Mod(600 grams) of wheat, or rice, or the price of that amount to a needy Muslim for each missed fasting day.

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

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