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.
Can someone who begins a voluntary fast break it?
It is preferable for someone who begins an act of worship not to break it.
Allah the Exalted has said {what means}: "and let not your [good] deeds come to nought!" [Muhammad/33].
However, if a person starts a voluntary fast (nafl) and needs to break it, they are going against what is preferable, but there is no sin upon them.
Does collecting saliva and swallowing it break the fast?
Swallowing collected saliva does not break the fast, but it is an unnecessary and meaningless act.
I wish to purchase an online account (a gaming account), and its ownership will be transferred to me. However, my friend will purchase it on my behalf, and I will repay him in deferred installments with an added profit margin to account for the installment sale. What is the ruling of Islamic Law on this transaction?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
The ruling on selling electronic games depends on the ruling of the game itself: if the game is permissible, then selling it is likewise permissible. However, if the game contains Sharia violations that render playing it impermissible, then selling it in that case is neither valid nor permissible. Therefore, we advise the necessity of reviewing the Sharia guidelines for electronic games set forth in Fatwa No. (3369).
Accordingly, if the game is permissible, a person may purchase it, take legal possession of it, and subsequently sell it in deferred installments for a price higher than its purchase price. The General Iftaa' Department has permitted dealing through Murabaha, while emphasizing the necessity of observing the Sharia conditions required for this transaction; please refer to Fatwa No. (2861). And Allah Almighty knows best.