Deception and Lies

Classmates taking pictures of an exam paper from the teacher's laptop

Q: In our class some boys took an exam paper from our teachers laptop when he was out and they took pictures of it and maybe that is the same paper which the teacher is going to give us for the final exam. They did a wrong thing. I didn't have the courage to stop them. What should I do now? If I complain then all the boys will be saying bad words to me and they will mock me etc. But I dont need sin. And maybe if they dont get that paper then they will fail and maybe need to repeat the whole year (so much time and money will go to waste waste). What should I do? 

Using a stove in hotels that do not permit the usage of appliances in hotel rooms

Q: It is a general rule in most present day hotels that visitors booked in are not allowed to use a stove or any such appliance in the bag which may be a cause of a fire. Despite the above condition, a person still uses the appliance without it being detected by the hotel, will this be incorrect and be regarded as khiyaanat (deception)?

Punishment for cheating someone

Q: In the year 2014 one guy told me that I got a job abroad and the total cost of visa and air ticket and everything is rs.177 000 so he insisted to pay him and I paid him rs.177 000 and after the payment he ran away cheating me. Later on I came to know that I was cheated. I just want to know whether he will be punished on the day of judgement for cheating me and moreover by default he will be punished by Allah because he is a kafir. So kafir will be punished by Allah for not worshipping Allah. 

Lying in a job interview

Q: My question is regarding lying on a telephone interview for a university application. I had a telephone interview for computing course. I initially applied for a different course for which I got accepted with an unconditional offer. When I decided to change I had a telephone interview and the Head of department asked me as to why I didn't retake my GCSE Maths Exam as i had a D. I don't know how was it impulsive or due to nervousness I said that I was working full time. So he said ok and asked about my other qualification which is the main one BTEC I.T. He was satisfied and gave me an unconditional offer. So the lie is that I actually have retook my GCSE Exam and Got the same Result. I was certain that I had put it on my original application but it seems I didn't. To my shock I said the lie. I was actually working though pretty much full time. On Registration the Uni only took my BTEC cert. Am I sinful? Will my earnings be Halaal?