Teaching students about interest bearing loans

Q: I have to teach students the advantages and benefits of taking loan and paying interest as it is given in the syllabus of finance.

Example: When a Company takes a small amount of loan and pays interest, it gets many benefits like tax deduction on interest paid and other benefits... I am just teaching and it is my job. I am not paying or using or consuming interest in my daily life as it is haraam. Please tell me if I am doing any sin or I will be punished for just teaching the syllabus to students? 

Validity of the nikaah

Q: A woman once tried to make a man fall in love with her. She said a dua, blowed into water and then gave the water to a man to drink to make him fall in love with her. She understood that she has done a wrong thing. She repented. Now whatever she has done, does it make marriage between the above man and woman prohibited?

Muslim manager advising the company to take out interest bearing loans

Q: I am working as a Finance Manager in a company. I perform various duties of my job like Financial Planning Analysis.., and one such duty is to advise the company on raising of money for the business and I advised to raise from equity and debt (loans)

On my advice the company takes small amounts of loans and pays interest (riba). It gets many benefits like tax deduction on interest paid and other benefits... But the company has to pay interest (Riba).

Since India is Darul Harb, I have no choice of interest free loans. Moreover I am just advising and it is my job. I am not paying or using or consuming riba in my daily life as it is haram.

1. Please tell me If I am doing any sin or will I be punished for just advising the company? Because I have heard Hadees that all those persons are sinful if they are involved in riba related transactions and riba is haram.

2. Is my job and salary halal?

3. If I am earning 1000 Rupees for 10 hours daily and I performed this riba Advise work for 1 Hour and Earned 100 Rupees, is it compulsory to donate that 1 hour salary of 100 Rupees as charity ?

4. Can I perform all my other duties

Making fun of Islam

Q:

1. If someone does kufr (by mocking islam) after that he comes to know its kufr, is it necessary to say shahadah and repent?

Case1: I am asking this because if a person doesn't know its sin, he won't be getting any sin right? Then why is shahadah and repentance required (if he is not gettig sin).

2. If I said to someone that "making fun of islam is kufr and whoever does this is, is a kafir and needs to repent and say shahdah again to become muslim." Instead of knowing the correct ruling, i just purposely told him to do repentance and say shahadah again to become muslim. Did i commit kufr by making halal haram by telling someone to do an act which is not required and telling them only if u do this then you become muslim.