What is the ruling on congratulating others on the arrival of Ramadan?
Congratulating others on the arrival of Ramadan is permissible.
If someone does it to express their love for worship and the blessings of Ramadan, and congratulates their fellow Muslim, they have done something good.
The Prophet ﷺ said: "Shall I not tell you something that, if you do it, you will love one another? Spread peace (Salam) among yourselves." [Narrated by Muslim]
Giving Salam is a prayer for peace and safety.
What is the ruling on using the *subḥah* (prayer beads) to count during *tasbīḥ* and *dhikr*?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is recommended to use the ordinary or electronic subḥah (prayer beads or counter) to count tasbīḥ, dhikr, and istighfār, because it helps one to remember Allah. Many reports have been transmitted from the Companions and the Followers (tābiʿūn) showing that they continued to use strings of date pits as an aid to dhikr and tasbīḥ.
It is one of the lawful means of worship. Indeed, what is established from the Prophet (peace and blessings be upon him), namely that he counted tasbīḥ on his right hand, shows that it is permissible to count tasbīḥ with whatever helps a Muslim keep track of the number. There is therefore no basis for calling it an innovation (bidʿah), and we know of no jurist who said so.
Al-Ḥāfiẓ al-Suyūṭī (may Allah have mercy on him) wrote a dedicated treatise on the subject titled al-Minḥah fī al-Subḥah, printed within al-Ḥāwī li’l-Fatāwī (vol. 4–6).
Shaykh al-Islām Imam Ibn Ḥajar al-Haytamī (may Allah have mercy on him) was asked: Does the subḥah have a basis in the Sunnah? He replied: “Yes, and al-Ḥāfiẓ al-Suyūṭī wrote on this. Among the evidence is what is authentically reported from Ibn ʿUmar (may Allah be pleased with them both): ‘I saw the Prophet (peace and blessings be upon him) counting tasbīḥ on his hand.’ Ibn Abī Shaybah, Abū Dāwūd, and al-Tirmidhī also narrated: ‘Hold fast to tasbīḥ, tahlīl, and taqdīs, and do not be heedless, lest you forget the affirmation of Allah’s oneness (tawḥīd). Count them on the fingertips, for they will be questioned and made to speak.’ Counting tasbīḥ with pebbles, date pits, and a knotted string has also been reported from a group of the Companions and those after them. Some scholars held that counting on the fingertips is better than the subḥah, based on the ḥadīth of Ibn ʿUmar. Others distinguished, saying: if the one reciting is safe from miscounting, counting on the fingertips is better; otherwise the subḥah is better.” [al-Fatāwā al-Fiqhiyyah al-Kubrā, Vol.1/p.152]. And Allah Almighty knows best.
Is it permissible for one who sacrifices on behalf of another, with the latter's permission, to eat from the sacrifice?
It is permissible for someone who sacrificed on behalf of another with their permission to eat from it with their permission, and they stand in their place (act as their representative) in distributing it.
It is stated in Nihayat al-Muhtaj ila Sharh al-Minhaj (Vol.8/P.141): "And he—meaning the one sacrificing on his own behalf, provided he has not apostatized—has the right to eat from a voluntary sacrifice and his sacrificial gift; rather, it is recommended. As for an obligatory sacrifice, it is forbidden for him to eat from it, whether it was designated as such initially or as a liability in his dhimmah. And excluded by what has preceded is if he sacrifices on behalf of another, or if he apostatized, then it is not permissible for him to eat from it, just as it is absolutely impermissible to feed a disbeliever from it."(The text I found indicates the impermissibility of eating) ???
And it is stated in Hashiyat al-Jamal ‘ala Sharh al-Manhaj (Vol.5/P.262): "If a person offers a sacrifice on behalf of a living person with their permission, does he act as their representative in distributing it—on the grounds that permission to sacrifice is permission to distribute it—or does it depend on their explicit permission? This requires consideration, but the first view is not far-fetched." And Allah the Almighty knows best.
Is it permissible to include others in the reward of one`s sacrifice?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is permissible for the person offering an Udhiyah (sacrificial offering) to include others in the spiritual reward of the sacrifice. However, it is not permissible for multiple people to jointly share the purchase price of a single sheep or goat, unless one person gifts the money to the other.
It is stated in Mughni al-Muhtaj (6/137) by Al-Khatib al-Shirbini:
"If a person includes someone else in the reward of his sacrifice and slaughters it on his own behalf, it is permissible."
It should be carefully noted that including someone else in the reward of one's sacrifice is completely distinct from offering a sacrifice on behalf of someone else. And Allah the Almighty Knows Best.