Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.

 

1- It is recommended to recite them in the morning and the evening.

 

2- Basically you are supposed to recite it yourself. Obligatory listening to the Quran is only meant during prayer. If you do not concentrate on recitation, there is no problem. It is, however, preferable to concentrate on what is being recited.

 

3- It only expiates minor sins. Major sins are forgiven through tawabah. Repentence has certain condition: First, your repentance should be meant for the pleasure of Allah. It should not be intended for showing off. Second,  you must express remorse for the sin you have committed. Third, you must give up this sin. Fourth, you must have a strong resolute not to make this sin again.

4- Yes it is.

 

Almighty Allah knows best.