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. 

Nikaah via text messages

Q: I have done a nikkah on message with my fiance without the presence of any witness but i took the snapshots of those messages as a proof but later after 8 months due to some misunderstandings i gave a tallaq to her later one more time i said "i end this relation right now in my full senses"(i didn't used the word tallaq second time) and later after one month due to misunderstandings i again gave tallaq 3rd time (by using the word tallaq) all these were done on messages i have snapshots of nikkah and tallaq as well and now we both are very afraid that if that nikkah was true or was acceptable according to shariah and if it is so the tallaq that i gave her was acceptable or not please help me out if both things were right then is there any way we both could be togather again and get the nikkah done or not??

Paying profit on a loan

Q: I have an interest loan which is fixed interest car loan. However i need a car for work and i am a salesman. I know this loan is haraam. I have asked family and friends to give me a loan but failed. Now I'm stuck with this loan and i would like to find out is there any place where i can get a sharia loan as i hate to be in interest. Please help as i have no barkat and i can pay any muslim willing to help me a profit rather than being in interest.

Doubts about following a mazhab

Q: I am a hanafi but I don't know I'm getting these kind of questions about mathabs for so many weeks now, like for example, why am I supposed to read salaah if I'm a hanafi when its 10+ days of haydh and I'm not supposed to if I'm a Shaafi or like why would I be a sinner if I didn't read salaah before Shaafi times end and and I'm not a sinner and I dont have to read qadha if im a Hanafi

1. I fail to understand why there are so many masaail that contradict each other so why do they?

2. Is qiyaas from sunnah?