Is it permissible to make up for missed fast after the beginning of the second half of the month of Sha`ban (the month before Ramadan)?
Yes, it is permissible, but one who had missed fasts should hasten to make up for them. As for the Hadith mentioned in this regard, the prohibition is for offering absolute voluntary fasting. And Allah Knows Best.
If the fasting of nine years has accumulated upon me, I wish to make them up by dividing them over several years, as it is difficult to fast them all in one year due to their large number. Consequently, expiation will be due on me. Is it permissible to pay the expiation after completing all the make-up fasts, even if it takes years?
If the fasting was broken due to a valid legal excuse, it is permissible to divide the make-up fasts over several years based on one’s ability. However, if a person passes away before completing the make-up fasts, the heirs must fast on their behalf or feed one needy person for each missed day.
If the fasting was broken without a valid excuse, one must hasten to make it up. Should the person die before completing the make-up fasts, the heirs must either fast or feed the needy on their behalf. As for the expiation, it is calculated after completing all the make-up fasts. And Allah Knows Best.
Is a woman`s neck an Awrah (private part)?
All Perfect Praise is due to The Lord of The Worlds.
It is an Awrah, and it is forbidden for her to reveal it before non-Mahrams (Marriageable men). And Allah Knows Best.
Is it permissible to offer Tahajjud prayer after Witr prayer?
It is permissible to offer voluntary prayer after Witr (An odd number prayer performed between Isha and Fajr) prayer. However, it is desirable that the night prayer be ended with Witr. Therefore, it is desirable for one, who thought that he was most probably going to wake up at night in order to offer Tahajjud, to offer Witr after it, but one, who fears that he might not wake up, should offer Witr before going to bed.