Acquiring Deeni Knowledge

Q: I am currently studying in a medical university. I want to share Islamic knowledge with my classmates. Is it permissible for me to make a WhatsApp group of my classmates, including both male and female, and then share Islamic knowledge on that group. There will be NO personal contact with any female.

There are already many other WhatsApp groups in which the whole class is added for study discussions. So if I use the same platform to spread Islamic knowledge, is it permissible?

Q:

1. Can you please list a few authentic Hadeeth Shareef books?

2. Other than Bahishti Zewar and Hayatul Muslimeen, can you name a few authentic books for reading? I have a lot of free time, and I want to fill my head with a little Islamic knowledge.

Q: What should a person do if he gets 2 different answers from different scholars of the same Hanafi fiqh? Will there be an issue if he ignores one?

Q: I plan to convert to Islam insha-Allah. I would like to know what Sufism in Islam is because the definitions I read on the internet do not make sense to me. I would also like to know because I heard it is bad and I would like to make sure that I stay away from those types of things.

Q: Should a person first read the Seerah of Nabi صلى الله عليه و سلم or the biographies of our (Indian) Akaabireen or vice versa?

Q: I learnt in Islam that it is very bad to reveal one's personal secrets to others, but is there any danger in teaching my Muslim brother something new I learnt about Deen like how to perform ghusl? 

Q: Can we teach orphans a lesson on parents in the subject of Akhlaaq. I'm teaching them Madrasah and in the Akhlaaq book there is a lesson on how we should respect and treat our parents with kindness.

Q: Is it compulsory to run a madrasah (Islamic Institute)? What is the role of a madrasa?

Q: In Bahishti Zewar, there are many masaail that speak about a husband who can have sexual intercourse with a minor. There was 1 certain masa'ala that (if a husband has sexual intercourse with a minor where there is a fear of her vaginal tissues coming together then ghusl is not fard upon her pg. 74 quoted briefly).

Mas'ala was quite graphic and gave me a headache just by thinking about it. My question is, won't that be considered as paedophilia. Does Islam really allow having intercourse with minors. If not then why are these masaail mentioned in Fiqhi books. Your detailed explanation will highly be appreciated.