Is it permissible to trim the eyebrows if they become excessively long?
Trimming eyebrows is permissible if they become excessively long, yet; it is reprehensible. And Allah Knows Best.
Is it permissible for the guardian, or the father of the child to hit the latter in order to teach him/her good manners?
It is permissible for the guardian to hit his/her child for teaching them good manners once they become ten years old provided that it is done mildly, harmlessly and without intimidation. Actually, such punishment is to be employed gradually i.e. after: asking, warning, and scolding. As for the teacher, he isn`t allowed to hit the student unless the latter`s father approves of it, and it is done according to necessity without intimidation, or harm.
My father placed shares worth twenty dinars in one of the banks, and their value doubled to become five thousand dinars. When my father passed away, one of the scholars told us that it is permissible for us to take the money. What is the ruling on this money, considering that it comes from a bank and involves interest (Riba)?
Allah The Almighty Said (What means): "And if you repent, then for you is the principal of your wealth. You do not wrong, nor are you wronged." [Al-Baqarah/279]. This is the precautionary ruling regarding what you are asking about. You are entitled to the principal amount, and you should give the excess as charity to the poor and needy. If you are poor, you may take from it. And Allah The Almighty Knows Best.
Should a person who doesn’t offer Tasbeehb (saying Subhaana Rabbiya Al-‘Atheem during Rukoo`, and saying Subhaana Rabbiya Al-A‘laa during Sujood) during Rukoo` and Sujood perform As-Sahw Sujood (prostration of forgetfulness)?
He/ she doesn`t have to perform Sujood As-Sahw, whether he/she didn`t offer Tasbeeh during Rukoo` and Sujood either intentionally ,or unintentionally, provided that the attentiveness of the heart wasn`t undermined since it is a pillar in both.