CBSE results

Yes, if you fail in more than one subject you have to repeat a year. Since you have an optional subject which helps you to pass if you fail in one subject only. But, it can not help if you fail in 2. The total percentage is 5 subjects. All the best.

Use this link:
https://www.shiksha.com/college-predictor

No, there is no official site as oldcbseresults.com by CBSE. So, I suggest you to better avoid it.

You can try by BA in History. The cut-off is usually above 95% for non-christian general category.

Yes, the CBSE board provide you a checking on the basis of step marking.
If your first step is correct and solution is wrong, then also, you get marks of first correct step but if your starting step is wrong and rest, solution is correct, then you get no marks.

If you do well in the paper, you will score well. There is no doubt that hardwork always pays off well. So, study well and appear for the exam with full preparations. I am sure, you will score well. All the best.

See, you can go through the counselling there. You can get any GFTI and then you can apply for the state universities as going to the GFTIs is far better than going to any state governed colleges.

If you pass in the next compartment, you will be shown as passed in 2018. For information regarding the next Compartment exam please stay in contact with your college or school. They will be able to help you better. Also keep checking the CBSE's website regularly for notifications.