Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
What should the one performing the slaughter say at the time of slaughtering the 'aqīqah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is Sunnah to say the following supplication at the time of slaughtering the 'aqīqah:
"Bismillāhi wallāhu Akbar, Allāhumma laka wa ilayka, hādhihi 'aqīqatu fulān."
("In the name of Allah, and Allah is the Greatest. O Allah, this is for You and unto You — this is the 'aqīqah of [the child's name].")
This is based on what al-Bayhaqī narrated in Al-Sunan al-Kubrā (Vol.9/P.511), that the Prophet ﷺ said: "Slaughter it in his name and say: In the name of Allah, and Allah is the Greatest. O Allah, this is for You and unto You — this is the 'aqīqah of so-and-so."
And Allah Almighty knows best.
What are the Sunnahs and etiquettes related to the slaughtering of an animal?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
1-The animal should not be terrified or frightened before it is slaughtered.
2-An animal should not be slaughtered in front of other animals.
3-It is recommended to offer water to the animal before it is slaughtered.
4-The knife must be sharpened before the slaughter to ensure that the esophagus, trachea, and jugular veins are severed as quickly and cleanly as possible. This is based on the Prophet’s (peace be upon him) saying: "Verily, Allah has prescribed Ihsan (excellence/proficiency) in all things. So, if you kill, kill well; and if you slaughter, slaughter well. Let each one of you sharpen his blade and let him spare the animal unnecessary suffering." [Narrated by Muslim].
5-One must not begin skinning or butchering the animal until its death has been fully confirmed.
6-Cows and Sheep: It is best to slaughter them while they are lying on their left side, facing the Qiblah. The right hind leg should be left untied so the animal can move it, which helps it remain more comfortable during its final moments. Unlike other livestock, it is preferred to perform Nahr (slaughtering by a swift stab at the base of the neck) while the camel is standing, with its left knee tied. And Allah the Almighty knows best.
Is a person who is in a state of Janabah (major ritual impurity due to having a marital intercourse, ejaculation, menstruation, and post-delivery impurities) sinful if he/she goes about his/her daily life activities in that state i.e. without making Ghusl (ritual bath)?
It goes without saying that a Muslim should always be in a state of ritual purity so as to be able to perform prayers and recite Quran. It is from Sunnah (Prophetic tradition) that a Muslim hastens to make Ghusl from Janabah, but he/she is not sinful in case he/she delayed that provided that he/she doesn`t miss prayers. However, it is permissible for him/her to go about their daily activities while in a state of Janabah, but had better bathe in order not to miss any prayer.
