What are our duties towards our Muslim brothers who have been stricken by calamities and disasters throughout the world?

On some trips there is a Qur'aan reading program, and they divide the people into separate circles (halaqahs) and someone who reads Qur'aan well to correct any mistakes. Is there anything wrong with this?

For how long does Allah forgive a person's sin? If he repents and seeks forgiveness from his sin, then goes and commits the same sin again, then he seeks forgiveness again then commits the same sin again, and so on, does Allah forgive him or does that mean that he is not sincere towards Allah, especially if he repeats that sin after a short while, but he does not stop seeking forgiveness?

A very common problem seen in youth in western countries is that their parents allow them to indulge in some form of haram in the hope that will stop them from committing worse haram. An example of this is that parents will say that they allow their children to indulge in music in the hope that will stop them from going out with bad people or leaving their home all together. Parents are afraid that if they enforce the law of Allah in their homes, that their children will leave. 

What is Islam's position on this sort of compromise? Some parents also say that they only have the duty to tell their children something is haram, and then their children have to choose for themselves because they are already young adults (i.e. 13 -18 years old and unmarried, living at home). Don't the parents have to forbid haram by all means, or do they just say that is haram and then leave them be? To what extent do parents have to go to forbid their children from haram?

Parents also believe that once their children reach the age of puberty they are no longer responsible for their sins or actions, and so say they will have no sin if they advise their children something is haram and then leave them. Is this true? Or do parents always have the responsibility of forbidding their children from haram, and will they be responsible if they see their children doing haram and just leave them after advising them?

How can we teach our children the adhkaar (words of remembrance) to be recited every day and night?

What is the ruling on mixing with kaafirs and dealing with them kindly, hoping that they will become Muslim?

In Australia during christmas there are huge discounts on things like clothing, furniture, electronics etc. is it permisible to shop to get this discount which is generally not available during other part of the year?

I tell non-Muslims that Allah created everything in this universe. They ask me who created Allah? How can Allaah have been there since the beginning? 
How can I answer them?

If a man was praying the sunnah of the fajr [prayer], or other than it, and whilst doing so the [iqaamah for the obligatory] prayer was called, is he required to [promptly] terminate his prayer in order to join the imaam [and congregation] in [the obligatory] prayer, or should he complete his prayer [first]?

I have a serious problem when purifying myself from major impurity, because I purify myself with a little water, then I wipe myself sometimes 21 times and sometimes more than that, yet I still see traces, which makes me purify myself again with water. Hence I spend a long time in the washroom in order to cleanse myself, which has damanged my health. What is your opinion? Is there a specific number of times for wiping oneself in order to become pure?.

Is it sufficient to use tissue only when cleaning oneself after defecating, or is it essential to use water?.