Nikaah & Marriage Issues

Q: Can my brother in law be regarded as a witness at my sister's nikaah while I, the brother be the wali?

Q: As a father, can one punish the daughter if she's a teenager? Islamically what physical discipline is permitted or should my wife do it?

Q: Is it permissible to continue a marriage if the mahr (dowry) has not been paid? 

I am currently married, but my husband has not yet paid the agreed-upon mahr (dowry). I would like to know if my marriage is still valid in Islam without the payment of mahr. What steps should be taken in such a situation? Is the marriage still considered valid, and what are the Islamic guidelines regarding mahr payments? Should I take any specific actions to address this issue?

Q: Can the husband disallow the wife to use phone or social media to talk to her parents etc. without any reason when the wife does no haraam acts?

Q: My husband didn't clarify about his previous marriage to me in our Nikaah certificate. He mentioned that he was divorced from his previous marriage but after our marriage he disclosed to me that his ex is still his wife and I am his second wife. 

My question is that, is our Nikaah done or because of his statement our Nikaah is not valid? Please clarify.

Q: If children throw food items in which Quran Aayaat was recited on. After that children they felt guilty for that act. What is the kaffara for this action?

Q: I would like to know as a wife, whether it is a right of mine that my husband spends some quality time with me after work and Esha or is it just me being demanding and ungrateful which is how my husband sees it. Most nights he is at his friend's houses till 11 or 12 and then comes home when I'm already asleep after I've been waiting for him for hours. 

Anytime I bring up an issue, he tells me the hadeeth about the women being the greatest inhabitants of jahannam due to their ungratefulness and keeps saying it's in my nature as a woman. I need to know whether I am just being that type of woman and I just need to be fine with not seeing my husband and just be content that he sleeps next to me at night when he does come home.

Q: Is it permissible for a husband not to have access/communication with his wife for 3 months based on a decision which was by her family... We are separated for 3 months..

Q: Is marriage of a Sunni (Deobandi) girl valid to a Shia boy?

Q: I got married approximately 9 years ago. At the time my wife and her father wanted Mehr e faatimi as mehr. However I could not afford the mehr e faatimi at that time. They then agreed to a lesser amount but I told them that insha allah one day when I am able to then I will give her the full mehr e faatimi amount. This was just verbally said and was not written down. 

Alhamdullilah I am now in a position where I can give her the full mehr e faatimi amount. I would like to know if I should give her the mehr e faatimi amount at that time (9 years ago) which was approximately R 12 500.00 or should I give her the mehr e faatimi amount of current value which is approximately R28 000.00?