Breaking a qasam

Q: I have a question. I'm recently divorced as my wife cheated on me with my own brother. Question I have is one day I was caught by my mum saying I love you to a girl and that we will sleep together. This was after my divorce. My mom was very upset and crying a lot so I didn't understand what to do, now she was tense I was tense and crying trying to calm her down. She then ask me to take kasam on her saying I will not look at any other girls fall in love or have sexual intercourse. We are humans and especially I know I will end up breaking the kasam. Is that kasam valid and if I do break it intentionally then what can be done to take the kasam off completely? Also once a kasam is broken is it no longer valid?

Issuing talaaq with a valid reason

Q: I want to marry another girl for that I want to give talaq to my current wife. She lives with her parents. I want to know can I give her talaaq by sending a talaaq note in a paper by post? I want to know what to write in talaaq paper? Simple written talaq will be acceptable or not or do I need any witness signatures?

Trying to locate the person one owes money

Q: I took my son to a general practitioner about 5 years ago. At the time, I forgot my medical aid card, but the doctor was kind enough to consult my son as I assured him to provide my details the next day. The next day, I contacted the receptionist and provided her my medical aid details. A year after that, I noticed that the fee did not go through my medical aid and contacted the receptionist to inform them. It is now a few years later, and the doctor has moved, and I am unable to get hold of him. He is not listed on any websites as well. How do I discharge this fee?

Impurity on clothing

Q: If a baby throws up on me or my clothes, can I still pray in those clothes or are the clothes napaak? Also, if a baby urinates on me or my clothes, do I or my clothes become napaak? Lastly, if the blood of another person touches me or my clothes, am I or the clothes napaak?

Can a person marry the daughter of the woman whom he committed zina with?

Q: My question is it permissible to have nikah with girl with whose mother I did zina? Now the story is that I did zina with a woman but the reality is that the woman did zina with me because I was 14 and she had three daughters at that time. Now my family did my nikah with her older daughter, she loves me and I love her and we happy for one another. I already did tawbah for what I did and I ask for forgiveness from Allah Almighty. Now we are in relationship already in nikah but I have a question sometimes in my mind, so is it allowed in Islam that her daughter be my lawful wife or I have to leave her? The zina one time we did almost 12 years passed, after that I never tried to do that with her mother nor her mother tried with me. Kindly answer me with details and references.

Doubting whether the discharge is mazi or mani

Q: I have a question which always brings doubt to me with regards to ghusal. This happens to me all the time like this morning when I got back home from fajr I went to use the bathroom and on taking out my underpants I found a tiny dot of wetness and small white marks on my underwear. I then urinated and whilst urine emitted I watched to see if anything odd is emitted, I found that a little of white liquid came out as well which was sticky. Is this mani or mazi? I always get confused and then get waswasas. Do I have to make ghusal or do I just put on clean underpants and make wudhu?