Kufr

Q: Please tell me what will be the correct way forward approved by shariah in the situations mentioned below: 

1. Married man who is married for 8 years became a father in 3rd year of marriage, whereas when the first year of marriage was completed he started doubting the authenticity of the Quran being divine and the preserved word of Allah. Though this individual started having doubts, became uncertain of Islam’s truth, yet continued praying salaah regularly and observing other rituals believing he is still in the fold of Islam. Apparently doubting Islam (I am saying this as I’m not aware of the correct ruling) makes a Muslim a kaafir, but what about a person who is ignorant about the ruling that doubting and uncertainty in Islam being true invalidates the faith of an individual. 

Very importantly what will be the status of the nikaah and child born after the phase of uncertainty in Islam and doubting Quran’s preservation started, as I reiterate again he was not aware that such doubts can make him a kaafir. 

Will a person be excused for his ignorance if he continued his life without a fresh nikaah and begetting children? 

Is the child deemed to be Islamically legitimate? Considering the fact the biological father was unaware that doubts have invalidated his Islam. 

2. The same married man, sometime before the birth of his child uttered some kufriya statements which were critical of Islam and similarly like in the first situation was not aware that his Islam is invalidated because of such a statement, hence did not renew his nikaah. 

Is the child born in such a union considered Islamically legitimate when his/her parents were unaware of the correct sharee ruling, moved on with their lives without renewing their nikaah?

Q: A long time ago, my parents told my young self that when my little brother comes into this world he will be able to bring stuff from Jannah that we want like a toy, and told us to make dua for it. We did eventually get it from our parents but I'm worried that my parents doing something like this is considered kufr and me and my parents joking about how I was really gullible about it is also kufr. I believe they were trying to make me have a closer connection with Allah.

Q: If a Muslim mocks or jokes about a depiction of an angel like in a TV show saying for example it looks like something from a video game, is it kufr in any way?

Q: I asked chatgpt to make some funny jokes on conversation between angels of the grave and some renowned atheists after their death. Is it kufr?

Q: 

1. What is the status of a Muslim ruler who aids Kuffaar against Muslims... Is he still regarded as a Muslim? 

2. Is it permissible to kill him even if he is regarded as a Muslim? 

3. Are there any actions that nullify a person's Islam despite him claiming to be one?

Q: Someone joked about Islam being a terrorist group (sarcasm). I knew that it isn't a good thing to say but the tone and way of saying made me laugh and then I stopped afterwards because I know this is wrong, and I also felt worried about this. I don't mean to condone such jokes. Is this kufr?