Not at all. We have used Vivo V5s during our reviews and found that despite using for longer hours, we did not encounter any heating issues.
Yes, you can use memory card in this phone.
Yes, you can get EMI on a debit card, conditionally, your card is eligible for it. Check with your bank (ICICI & AXIS) if your debit card is eligible or not.
Vivo V5s has ARM Mali T-860 MP2 graphic processor GPU.