Is prayer nullified by nose bleed?
All praise be to Allah, The Lord of The Worlds. Blood coming out of the nose, or a wound doesn`t nullify prayer regardless of its quantity. And Allah Knows Best.
Is it permissible to pay the Fitr Zakah (obligatory charity) of Ramadan on behalf of a dead person?
The Fitr Zakah of Ramadhaan isn`t due on one who had passed away before the sunset of the last day of Ramadan. And Allah Knows Best.
Is it permissible for one to give the Zakah (obligatory charity) to his indebted brother?
It is permissible for one to give the Zakah to his brother if he was indebted, or poor.
I have a date farm, and the dates come in different categories, and within each category there are different sizes. How is zakāh paid on the yield?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
If the yield reaches the niṣāb (the minimum threshold for zakāh to become obligatory) — which is five awsuq (plural of wasq), equivalent to (611) kg — then zakāh becomes obligatory upon it, at a rate of one-tenth ('ushr) if irrigated by rainwater (i.e., naturally, without the use of machinery), or one-twentieth (half of the 'ushr) if irrigated using machinery/equipment.
If the yield of dates consists of different varieties, then zakāh should be paid from each variety according to its respective proportion. If this proves difficult, it is permissible to pay from a medium-quality variety [representative of the average].
It is stated in Ḥāshiyatā Qulyūbī wa ‘Umayrah (Vol.2/P.22): "Different varieties are combined together [for the purpose of calculating the niṣāb] — such as the various types of dates, the various types of raisins, and so on — and zakāh is paid from each type according to its respective proportion. However, if this becomes difficult due to the large number of varieties and the small quantity of each individual type, then zakāh should be paid from a medium-quality variety among them — neither the best nor the worst — out of consideration for both sides [the giver and the poor recipient]. If one goes to the trouble of paying from each variety according to its proportion, this is also permissible." And Allah, the Exalted, knows best.