Creating a WhatsApp group of males and females to share Islamic 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?

Paying a penalty if one delays in paying an instalment and Takaful insurance when purchasing a car

Q: I'm buying a car from a bank as "Car Ijarah", but I have two confusions;

1. From which bank I buy a car as per "Car Ijarah", they also ask us to sign on the contract where the condition is "If I delay the monthly installment then I've to pay some extra money as charity" as per their saying, but Alhumdulillah we have a shop and we are sure that we will be able to pay all installments on the time or before the deadline. So If I sign the contract and pay all the installments on the time will it be halal to buy that car from the bank?

2. The bank also want us to pay some extra money in down payment for takaful insurance of that car because in the period of installments which is 2 or 3 years the car owner of that car will be the bank, and as per we believe that insurance is haram so can we pay that money also? Because the owner is bank and after the period of installments they'll gift us that car.

Memorizing a Surah and imagining one is reciting it in front of people

Q: Someone is trying to memorize Surah Yaseen and recite it like Omar Hisham al Arabi. But when she try's to recite it, she imagines that shes doing it in front of people and imagines that she will recite to others later. She feels sad thinking that she can't focus on the fact that it should be only for Allah.

Should she stop memorizing? Should she take an oath that she will never recite "like that" in front of people? She also thought that she would recite beautifuly like that in front of her future husband. Is there any duaa for this?

Receiving the rewards of reciting the daily surahs when recited in nafl salaah

Q: Will we get the respective rewards and benefits of reciting Surah Waaqiah, Surah Mulk and Surah Sajdah if we recite these surahs in nafl salaah (Tahajjud) at night or do we have to recite these surahs before sleeping without being in the state of salaah? Similarly, by reciting Surah Yaseen in Ishraaq salaah, do we get the rewards and benefits of reciting it in the morning as mentioned in the ahaadith.

Accepting a gift from one's na baaligh sister

Q: I was studying Arabic and my sister, who was about 11 or 12 years old, gave me an Arabic learning book that my uncle gave to her. I would use this book for my class and then at some point after, I mentioned to my father that she gave me the book and my father didn’t object to that.

I have recently been told that this was not a valid gift and a Wali can’t hand over the property of the child and that the gift of a child to an older person is not permissible. The father is also not allowed to give or allow the gift of his child without something in return. If at the time I thought this was valid, such as the Wali knowing (my father), what should I do?