Sawm (Fasting)

Bismihi ta'ala

If the 10 year old is a female, who has reached her shar'i age of bulugh, then yes, she will need to pay the kaffarah of 'feeding 60 poor', along with doing the qadha' of that day. 

If it was a male, then no, he does not. 

And Allah knows best. 

Bismihi ta'ala

There are a few highly recommended things at the time of iftar, when you are going to break your fast. 

1. Praying on time. Prior to adhan, be ready for prayer, so when you hear the adhan, you pray on time. 

2. Before you break your fast with food/water, recite this:

اللَّهُمَّ لَكَ صُمْتُ وَ عَلَى رِزْقِكَ أَفْطَرْتُ وَ عَلَيْكَ تَوَكَّلْتُ

Allaahumma laka sumtu wa a'laa rizqika aftartu wa a'layka tawawkkaltu

O Allah, I fast for You, and I break the fast with the food You give me, and I rely on You.

There is another narration, from Imam Ali (a.s.) that says when he broke he fast he would say:

بِسْمِ اَللَّهِ اللَّهُمَّ لَكَ صُمْنَا وَ عَلَى رِزْقِكَ أَفْطَرْنَا فَ‍تَقَبَّلْ مِنّٰا إِنَّكَ أَنْتَ اَلسَّمِيعُ اَلْعَلِيمُ

3. Once you recited this dua, recite Surah al-Qadr, and then break your fast.

4. It is also recommended to pay sadaqah at the time of iftar. 

With prayers for your success.

Bismihi ta'ala

In these matters it is crucial to refer back to your Marja' taqleed, for the specific ruling, but from the view of A. U. Seyid Sistani, if you were confident you did not have to redo those days as qadha', you do not need to pay kaffarah, but you do need to redo those days as qadha`.

And Allah knows best.

Bismihi ta'ala

In the case of haydh, the maximum number of days that you do not pray/fast would be 10 days, depending on the circumstances you are in. 

If your blood is continous, then you will need to find out where during this period is your haydh days, and the rest being istihadhah. With the istihadhah days, depending on how much blood there is, you will still be able to pray and fast. 

Please familiarise yourself with the rulings of haydh/istihadhah, and below is a presentation that could help you towards this, in shaa Allah:

And Allah knows best. 

Bismihi ta'ala

Engaging in haram acts does not mean one abandons their devotion to Allah ta'ala and their 'ibadah. 

Indeed, it is even more important to stress on that, for the purpose of hopefully empowering oneself to become more obedient to God and stay away from sin. 

Yes, this man should continue to pray, fast, and perform everything else required by him as a Muslim. If done in the correct way, they will also be valid as well. 

With prayers for your success. 

Bismihi ta'ala

If what you mean by deliberately is that you did not have a valid excuse, then you must:

1. Repent to Allah ta'ala, asking for His forgiveness, if you have not done it yet.

2. Pay the kaffarah, of feeding of 60 poor people.

3. Redo those days, as qadha', and you redo only the days you are certain of, which would be the least amount. In this question, it would be 12 days of qadha`. 

And Allah knows best. 

Bismihi ta'ala

If the 40 years of fasting that they missed was with a valid excuse, then all they need to do is pay a 'fidya' for each day. A fidyah is 3/4 of a kilo of food, given to poor. 

If they did not have an excuse, then they must:

1. Repent to Allah ta'ala.

2. Pay kaffarah for each day. Kaffarah is feeding of 60 poor people (most common option). 

3. Write in their will that they have this amount of qadha' fasting to be done once they die, either by their next of kin, or they pay someone who will fast as qadha` on their behalf. 

Furthermore, from this holy month of Ramadhan, because they cannot fast, they can pay the fidyah.

And Allah knows best. 

Bismihi ta'ala

It is permissible to place something solid in one's mouth while fasting, for the purpose of cooling down, or naturally creating saliva, as long as it is not swallowed, or taken out and placed back in mouth again.

An example for this is putting a coin in your mouth.

And Allah knows best.