What is the ruling on performing voluntary (nafl) prayer during the time of istiwā' (the sun's zenith) on the day of Jumu‘ah (Friday), and is this ruling specific to someone who has come to the mosque to perform the Jumu‘ah prayer?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
It is permissible to perform voluntary (nafl) prayer during the time of istiwā' (the sun's zenith, i.e., its highest point before noon) on the day of Jumu‘ah (Friday) — whether for someone who is attending the Friday prayer or someone who is not, and whether they are among the people obligated to attend it or not.
It is stated in Mughnī al-Muḥtāj (Vol.1/P.310): "The more correct position (al-aṣaḥḥ) is that prayer is permissible during this time without restriction — regardless of whether the person will be attending the Jumu‘ah prayer or not." And Allah, the Exalted, knows best.
Is it permissible for the guardian to give Sadaqa (voluntary charity) from the money of the orphans?
It is impermissible for the guardian to donate from the money of the orphans because he is entrusted with the safekeeping of that money, and is prohibited from donating it.
What is the ruling on someone who eats or drinks thinking that the night is still present, then realizes that dawn has broken?
Whoever eats or drinks thinking that the night is still present, then later discovers that dawn has broken, must refrain from eating and drinking for the rest of the day out of respect for the sacred month. However, they must make up that day after Ramadan, and there is no sin upon them.
Is it valid to perform Tarawih prayer at home?
It is Sunnah for a Muslim to perform Tarawih prayer in congregation at the mosque.
However, if a person sometimes prays it at home in congregation with their family for a valid reason, there is no harm in doing so.