Is it permissible for women to gather in one of their homes to pray Tarawih?
Yes, it is recommended (mustahabb) for women to pray Tarawih in congregation if they gather, even if it is not in the mosque.
In fact, praying at home is better for them, as it avoids the potential concerns associated with going to the mosque.
What is the ruling on sending blessings and peace upon the prophet (PBUH) after the Adhan?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
It is a Sunnah to send blessings and peace (As-Salat wa al-Salam) upon the Prophet ﷺ after the Adhan and the Iqamah, for both the caller (Mu’adhin) and the listener. It is permissible to do so aloud after the conclusion of the Adhan. However, it is preferable to maintain a brief pause between the words of the Adhan and the prayers upon the Prophet ﷺ, so that people do not mistakenly assume that sending blessings upon him is an integral part of the Adhan itself. And Allah the Exalted knows best.
Should the Zakah (obligatory charity) giver tell the poor recipient that this is the Zakah of his money?
No, he shouldn`t. But, the Zakah giver should make an intention in his heart that it is the Zakah of his money when paying it to the poor. And Allah Knows Best.
Should one who doesn`t perform prayer out of laziness make it up later, and how should he/she do so?
All perfect praise be to Allah,The Lord of The Worlds He/she is obliged to make up missed prayers by offering with each obligatory prayer another one, and if he/she offers two, then it is better. And Allah Knows Best.