Mistakenly reciting a surah instead of attahiyyaat

Q: Is Salaat valid in the following cases? If so, please advise what should be done if such an error occurs in the Salaat.

1. Mistakenly reciting thana twice.

2. Mistakenly reciting some Ayaats of a Surah, or an entire Surah, instead of tashahhud. Tashahhud is then recited after the mistake is  realized.

3. Mistakenly reciting some part of tashahhud, or the entire tashahhud, instead of Surah Fatiha. Surah Fatihah is then recited after the mistake is realized.

Unmarried woman getting pregnant through artificial insemination

Q: A Muslim sister in a certain Islamic community got pregnant. The Islamic leaders decided to discipline her since she was not married. When the elders of the Community met her, she told them that she has stayed in the religion for years and no one is marrying her and she is getting to the age where she can't get pregnant if married. So she went and did artificial insemination since she wants a child. She provided the medical documents that showed that she has done the artificial insemination. The sister is pregnant without committing fornication nor adultery. Is she sinful?

Spotting after abortion

Q: I have questions related to Islamic activities like prayer, reciting Quran and fasting, sexual relations, etc. My wife was pregnant for 2 month's but the growth of the embryo has stopped after 1 month(4 weeks). After 2 month's we came to know the problem and the doctor advised to get D&C (abortion). Now even after 12 days, her menstrual cycle has not started and she is just spotting after 1 or 2 days on her pad. I want to know Islamically, do we consider it as menstrual bleeding or istihada?

Clarification regarding an incident of Hazrat Moosa (alaihis salaam) and Hazrat Haaroon (alaihis salaam)

Q: I'm clarifying a question. I was listening to a dars which was telling about a conversation between Hazrat Musa (alaihis salaam) and Hazrat Haroon (alaihis salaam). I couldn't listen to the whole dars but I heard a sentence that the narrator was saying that Musa (alaihis salaam) said to Haroon (alaihis salaam) that 'You were a better Khalifa than me, why didn't you guide people in my absence?'. Is this waqia mentioned in the Quran?

Husband lying about the value of the mahr jewellery

Q: I am in dire need of advice regarding dowry (mehr) in Islamic marriages. Jewellery of an x amount was given at the time of the nikkah as mehr. I have had doubts about the amount and when I asked my husband he refused to provide a slip, or say where it was purchased from. However upon investigation the findings are that the jewellery is worth 50 to 75% less than the price that was stipulated. Even the selling price would never have matched the price that was stipulated. What is the ruling on this? Is the nikaah still valid?