During the first day of mourning (aveilus), is the mourner prohibited from wearing tefillin, and when does he resume?

Is it permitted to pass gas during prayer when wearing tefillin?

Bodily Needs During Prayer

Is it permitted to request personal needs during the first three or last three blessings of the Amidah?

Qualifications of Prayer Leader

Is it permitted to request communal needs (e.g., Ya'aleh v'Yavo, Zochreinu l'Chaim) during the first three or last three blessings of the Amidah?

Qualifications of Prayer Leader

When one bows during Zokhreinu or Mi Kamokha on Rosh Hashanah/Yom Kippur (insertions in the first and second blessings of the Amidah), must one straighten up before the blessing's conclusion?

Mashiv HaRuach — Wind and Rain

May a prayer leader who enters the synagogue during the congregation's silent prayer immediately lead the repetition without first praying silently?

Repetition of Amidah

Must one raise (or keep lowered) the hands during ritual washing to prevent first-waters from flowing back past the wrist joint?

Washing Vessels and Water Sources