joke

Q: A senior South African Tablighi worker made a joke about the laws of inheritance being in Surah Lahab. He said the verse says "Ma ka sab," meaning everything goes to the mother. Would this joke of his amount to kufr and invalidate his nikah? What about the people who laughed at the joke? Is this not a mockery of the Kalaam of Allah?

Q: Person A tells Person B the following joke. He says the memon was in Jahannam when he met his friend. His friend said to him that you were so pious, how did you end up here? The memon replied that I have a place in Jannah, but I put my house in Jannah on rent. Person B laughed at the joke. I am aware that in Surah Tauba that there is a verse which speaks about joking about Allah and his signs and this leading one to come out of the fold of Islaam. In the scenario presented above, do both A and B lose their Imaan and in the process invalidate their Nikah?

Q: If a man says to his wife "I divorce you" three times as a joke and has no intention to divorce her and is unaware that simply uttering the words could lead to divorce. Is that counted as talaaq or is the nikkah valid. Also note that this occurred while the wife was in a state of purity, before menses, during which intercourse had taken place. Is this nikkah still valid? Is the talaaq valid? If yes is it counted as one or 3? This occurred between a couple that are very much involved and would be devastated by talaaq. And please advise what should be done after this.