Comment on Taxation for Traders - Introduction
1. Ideally you should not use that normal trading account any more .You will have to convert this into a NRI trading account. NRI’s are not allowed to directly trade on F&O, it has to happen through a custodian. It is a time consuming process to open a custodial account and won’t make sense to open one unless you are planning to trade aggressively. The other option is to trade on F&O through any of your family members account.
2. Yes, you can and this is also exempt from long term capital gain. But do change the status of your trading/demat to NRI.
3. Same as above.
Check this link which explains how an NRI can get started and documents required.