Does using a wet miswak while fasting break the fast?
A fasting person should ensure that the miswak is dry when using it.
However, if the miswak is slightly moist but does not release any liquid when squeezed, then its use does not break the fast.
What is the ruling on the Friday bath (ghusl al-Jumu'ah)?
The Friday bath is a confirmed Sunnah, based on the Prophet's (peace be upon him) saying: "Whoever performs ablution on Friday, it is good for him, and whoever takes a bath, bathing is better." (Reported by Abu Dawud and al-Tirmidhi who said it is a hasan hadith). It is recommended for everyone who wants to attend the Friday prayer, even if they are not from its usual attendees, like a woman or a boy.
If a person is in a state of major impurity (junub) and intends by his bath both lifting the major impurity and the Friday bath, he achieves both. If he intends only one of them, he achieves only what he intended. And Allah the Almighty knows best.
Is it permissible to include others in the reward of one`s sacrifice?
Praise be to Allah, and prayers and peace be upon our Master the Messenger of Allah.
It is permissible for the one offering a sacrifice (al-muḍaḥḥī) to include another person in the reward of the sacrifice, but it is not permissible for them to share in the price of the sacrifice. It is stated in Mughnī al-Muḥtāj (Vol.6/P.137) by al-Khaṭīb al-Shirbīnī: "If he includes another in the reward of his sacrifice and slaughters it on his own behalf, it is permissible." And Allah Almighty knows best.
Is it permissible for a wife to boycott (not to attend to his different needs) her husband?
It isn`t permissible for the woman to boycott her husband unless he is the reason behind that, and it is recommended that both spouses seek the advice of righteous people to make reconciliation.