Is it permissible for one to shake hands with his uncle`s daughter?
No, it isn`t because he is a non-Mahram (Marriageable) to her.
Does passing wind from the anus affect ritual purity?
Ablution is nullified by the passing of wind from the anus, but washing the anus is not required as wind leaves no impurity.
If a traveler settles or a sick person recovers while fasting, is it permissible for them to break their fast?
● If a sick person starts the day fasting and then recovers during the day, they must complete their fast.
● If a traveler starts the day fasting and then settles (returns or stops traveling) during the day, they must also complete their fast.
● It is forbidden for both of them to break their fast because the concession (rukhsah) is no longer valid once its reason disappears.
Does passing wind, from the anus without a smell, invalidate prayer?
If a person is certain of having passed wind even if it was with no smell, then both his/her ablution and prayer are invalidated, thus he/she should remake ablution and re-perform prayer.