Nikaah & Marriage Issues

Husband asking the wife to pay towards purchasing the child's nappies

Q: My son is 3 years 5 months. My husband is telling me to potty train for few months. I am not training him due to the fact that I trained my first one at this age and he messed napaak everywhere.  I told my husband I will try this month to train him and he told me if his not trained then I will have to pay a portion for his nappies. I feel very hurt as he buys vape and uses which is a high expense too. I want to know is this Islamically correct for him to tell me that I should contribute?

Receiving talaaq from the "second husband" while still in the first husband's nikaah

Q: A man had previously asked me to marry him in the presence of two witnesses and I said yes. This was years ago. 

My husband currently went through my phone and saw a chat regarding this marriage. He asked me about it which I said it was invalid as it was not conducted with a wali. My husband said it is valid. After having checked a Muslim girl can marry herself without a Wali. 

My husband promised marriage to me again if I take a talaq from the previous boy which I did and then he, my current husband will make a new nikkah. 

After doing all of this, all of a sudden my husband current gave me a third talaq. Now we are in a dilemma as to whether I can make nikkah with my second husband again as his nikkah with me was not valid.

Nikaah with a woman who is still in her first husband's nikaah

Q: I recently got married but we are now finding out that the girl did not get talaq from her first husband and the girl relied on a civil divorce to constitute the talaaq. 

The first husband of this girl says he didn't institute talaaq and the civil divorce was only for the courts. 

The second nikah has taken place before we found out. Is it valid?

Arm wrestling with non mahrams

Q: About 7–8 years ago, when I was newly married (around 1 year of marriage), my husband suggested we do arm-wrestling for fun. With his permission, I also did arm-wrestling with his four brothers. At that time, I did not feel any lust or desire from my side at all. 

I noticed that the brothers looked a bit excited, which could have been because they had never held a woman’s hand before but now I am worried. What if they might have felt lust at that time, 1 of them asked for a re match even though I lost from all of them but I said no 1 time is enough now I cannot ask them directly as it would be very embarrassing and it was almost a decade ago. Now I do proper hijab and cover my face too. 

My question is: Does this cause hurmat-e-musaharat, and is my nikah still valid? 

I also suffer from waswas (intrusive doubts) in religious matters, so I want clarity and peace of mind.