Does the clipping of nails nullify ablution?
No, it does not, and it is preferable to wash the hands afterwards.
What are the signs of Laylat al-Qadr?
It is said that among its signs are:
● A sense of peace and tranquility during the night.
● The sun rises on the following morning white and without strong rays.
However, one should not be preoccupied with searching for its signs at the expense of worship. Allah has hidden its exact date so that we strive in worship throughout multiple nights, ensuring that we attain its great reward.
Does the intention (niyyah) of the principal (muwakkil) suffice for the sacrifice (dhabḥ) of the udhiyyah?
Praise be to Allah, and peace and blessings upon our master, the Messenger of Allah.
If a person appoints an agent (wakīl) to perform the slaughter (dhabḥ) on their behalf, the intention (niyyah) of the principal (the one appointing the agent) suffices, and there is no need for the agent to have this intention himself. In fact, even if the agent is unaware that he is performing the sacrifice on someone's behalf as an udhiyyah (sacrificial offering), this does not affect its validity. And Allah, the Most High, knows best.
Is it Sunnah to cook the meat of the 'aqīqah?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
It is Sunnah not to distribute the meat of the 'aqīqah raw. Rather, it is recommended to cook it with something sweet — such as raisins or honey — as a good omen and expression of hope for the sweetness of the newborn's character and conduct throughout their life. And Allah Almighty knows best.