A group of about thirty young men will go to a farm on Friday. Is it permissible for one of us to deliver the sermon (*khuṭbah*) and lead us in the Friday prayer, or is it necessary to go to the nearest mosque?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
The Friday prayer (Jumuʿah) is not obligatory upon a traveler, whether his journey is long or short, if he leaves his place of residence before the time of Fajr begins, according to the Shāfiʿī school. If, however, he sets out on his journey after the Fajr adhān, then he is obliged to perform the Friday prayer, whether in his own town or in any town where the Friday prayer is held.
It is stated in Bushrā al-Karīm (Vol.1/p.383), one of the books of the Shāfiʿī school: “[The Friday prayer] is not obligatory upon a traveler on a permissible journey, whether long or short, if he departs from his place of residence before dawn.” End quote.
Accordingly, if you set out on your journey after Fajr, you are obliged to perform the Friday prayer in the mosque. The same applies if you set out after that, since you would not have fulfilled the conditions for the validity of the Friday prayer, among them: that it be attended by forty men who are free, adult (bāligh), sane, and settled residents of the place where Friday is held. It must be held within a cluster of connected buildings, whether a city, a village, or a district (liwāʾ), for what counts is the gathering of the buildings. And Allah Almighty knows best.
How do I deal with whispers (waswasa) in ablution and purification?
Whispers in ablution are from Satan, and the Muslim should not pay attention to them. He is not required to re-perform ablution or repeat washing a limb because of waswasa. He should always base his purification on its being valid. It is recommended for him to frequently say "La ilaha illa Allah" (There is no god but Allah), because Satan recoils when Allah is mentioned. And Allah the Almighty knows best.
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.
Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.