Conditions for the validity of Nikaah

Nikaah without witnesses

Q: I did ijab o qbul without mehar and wali and without witness 8 years ago. There was no physical relation but I realized it is wrong. I left that boy now and my father is getting me married to my cousin. Should I get married to him or tell my father about the nikah 8 years ago?

Making a marriage public via social media by posting pictures of the couple to have more people to witness the nikaah

Q: Is it permissible to make a marriage public via social media?

For example, since a marriage must be made public, can I post a photo of my spouse and me together on Instagram since I will then have more than two witnesses? Does that meet the condition of making marriage public, which the Prophet insisted upon?

Witnesses being present when taking consent from the girl at home before the nikaah

Q: In my country, before the actual nikaah, the qadhi goes to the bride's house to get her signature. Some people insist that there should be 2 witnesses there and some say no since this is not an actual nikaah but just to confirm that the bride has given her permission.

What is the ruling here? Should there be 2 witnesses when the bride gives her approval at her house and they have to be present in the nikaah to confirm that OR the mere statement of a wali during the nikaah (that my daughter has given her approval) is taken to be sufficient without the involvement of any witness (to confirm the above)?

Will nikaah takes place if a boy asks a girl “will you marry me”?

Q: What’s the maslah pertaining to the question “will you marry me”?

I learnt a while ago that whether it was done in a school play for example and the boy had to ask the girl or vice versa “will you marry me” and she said yes, they are married? What would be the maslah and how would the marriage be terminated?

What would happen if it happened on WhatsApp or in private? Would they still be married? And how would the marriage be terminated?

What would be the maslah if the people don’t know about the maslah of getting married in this way and they did it? I have a friend who went out with a group of friends and this girl asked him will you marry me and he said ya I will and they were with other friends? Are they married and what would be the next step?