What is the ruling on seeking forgiveness between the two Friday sermons?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
It is permissible to seek forgiveness (Istighfar) between the two Friday sermons (Khutbatayn), and it does not invalidate the Friday prayer (Salat al-Jumu'ah). Furthermore, it is not disliked (Makruh) to speak before the sermon, after it, or between the two sermons. Likewise, it is not disliked for one who enters during the sermon to speak if there is a need for it, provided he has not yet taken a place and settled into it. And Allah the Exalted knows best.
Can someone who begins a voluntary fast break it?
It is preferable for someone who begins an act of worship not to break it.
Allah the Exalted has said {what means}: "and let not your [good] deeds come to nought!" [Muhammad/33].
However, if a person starts a voluntary fast (nafl) and needs to break it, they are going against what is preferable, but there is no sin upon them.
For some time I have been searching for a guiding shaykh to teach me the spiritual path (*sulūk*) and the Islamic sciences, but I have not found one. What should I do?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
There is abundant good in this Ummah, and the scholars who guide and nurture are never cut off. The student of knowledge should strive in seeking them out, ask diligently after them, and draw from their learning.
As for one who cannot find a guiding and nurturing shaykh, he should send abundant prayers and peace upon our master the Prophet (peace and blessings be upon him), while keeping constantly to dhikr and worship and abstaining from the forbidden. For that will bring him to his goal in traveling toward Allah the Exalted. Imam Muḥammad al-Sanūsī (may Allah have mercy on him) said: “I have seen it said by some of the imams of Sufism that whoever lacks shaykhs of spiritual training (shuyūkh al-tarbiyah) should increase his invocation of blessings upon the Prophet (peace and blessings be upon him), for by it he will reach his goal.”
The scholar Aḥmad Zarrūq al-Mālikī (may Allah have mercy on him) said in Qawāʿid al-Taṣawwuf (p. 86), rule no. 114: “Dhikr is the decree of sainthood (manshūr al-wilāyah). Whoever is given dhikr has been given the decree. Our shaykh Abū al-ʿAbbās al-Ḥaḍramī (may Allah be pleased with him) said: ‘Keep constantly to dhikr and abundant blessings upon the Messenger of Allah (peace and blessings be upon him), for it is a ladder, an ascent, and a path to Allah the Exalted when the seeker does not meet a guiding shaykh.’” And Allah Almighty knows best.
Is it permissible for a praying person to make supplication in each Sajdah (a prostration) of obligatory prayer?
It is permissible for a praying person, whether praying individually, or in congregation, to make supplication during Sujood (prostration) in obligatory, or voluntary prayers. However, it is disliked for the Imam to do so since he is required to spare the prayer performers any sort of hardship, unless he is leading a certain group who don`t mind him extending the prayer.