Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
What is the ruling on Tarawih prayer?
Tarawih prayer is a confirmed Sunnah (Sunnah Mu’akkadah).
Is a person rewarded for refraining from all that breaks their fast when required to do so, and is it considered a valid fast?
If a person eats or drinks thinking that Fajr has not yet arrived, but then someone informs them that Fajr had already begun, they must refrain from eating for the rest of the day and make up the fast later.
If they observe the required restraint (imsak), they will be rewarded for obeying the command because fulfilling an obligation brings reward.
However, this is not considered a valid fast in terms of rulings. For example:
● It is not disliked (makruh) for them to use a miswak after noon.
● They are not encouraged to hasten the breaking of the fast at sunset.
● Other fasting-related rulings do not apply to them.
Who is the one required to slaughter the 'aqīqah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is Sunnah for the 'aqīqah to be slaughtered by the guardian of the newborn — the one upon whom the child's financial maintenance is obligatory — provided he is financially capable of doing so. 'Alī ibn Abī Ṭālib, may Allah be pleased with him, reported: "The Messenger of Allah ﷺ performed the 'aqīqah for al-Ḥasan with one sheep." — Narrated by al-Tirmidhī. And Allah Almighty knows best.