1) I dont know for sure
But i`m only guessing because of experience with my husband. When you buy something on EMI, no matter from where, the whole amount is 'blocked' from your credit card, but you will be only 'due' the monthly amount each month - like you wont need to pay the whole sum of it when the CC payment will be due, but only the monthly instalment.
It is just so that they (bank people) are certain that you dont overuse cards limit.