Is it permissible to pay the Zakah (obligatory charity) for settling the debt of a deceased relative?
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. And Allah Knows Best.
Can I start fasting based on the moon sighting of another country?
You must follow the moon sighting of the country you are in.
When is supplication (du‘a) more likely to be accepted: before or after breaking the fast in Ramadan?
Du‘a is accepted at all times, and this is part of Allah’s mercy and generosity toward His servants.
The Prophet ﷺ said: "No Muslim makes a supplication that does not involve sin or severing family ties except that Allah grants them one of three things: either He grants their supplication immediately, or He stores it for them in the Hereafter, or He averts from them an equivalent harm." [Narrated by Ahmad]
However, in Ramadan, du‘a is especially likely to be accepted shortly before breaking the fast.
The Prophet ﷺ said: "Three supplications are never rejected: the supplication of a fasting person until they break their fast, the supplication of a just leader, and the supplication of an oppressed person. Allah raises it above the clouds, opens the gates of heaven for it, and says: ‘By My might, I will surely grant you victory, even if after a while.’" [Narrated by Al-Tirmidhi]
If the bleeding ceases after 40 days following childbirth, but then returns intermittently during two days of fasting, what is the ruling?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Whenever the post-natal bleeding (Nifas) ceases and the woman is certain it will not return, she has become pure; therefore, she must perform the ritual bath (Ghusl) and resume praying and fasting. However, if the blood returns within fifteen days of its cessation and before sixty days have passed since the delivery, the ruling of Nifas applies once again. Consequently, any fasting or prayer performed during that interval of purity is rendered invalid; she must make up for the missed fasts of those days, but she is not required to make up for the prayers. And Allah the Exalted knows best.