Updating my NRI status for KYC,mutual fund,stock and other investment?

I have my investment made as indian resident. Now i am planning to register myself as NRI since i moved to US for employment from last year.
Mutual fund,Stocks,savings account,KYC all are created and registered as resident. Now when i ask my banker he is suggesting me to close all this and reopen new account.

I dont want to redeem mutual fund/sell stocks but would like to retain them and update my status alone to NRI. Is that possible?

Can the derivative segment be activated on two accounts with two brokers on nse?

Suppose I have two trading accounts with two separate brokers in india. Now, can the derivative segment be activated on both accounts or not? Can I trade in derivative on both accounts ? Can I place order and reverse orders both using two accounts with two brokers i.e. If I place a buy order in any stock future on nse on my first brokers account, then can I place a sell order also on the second account to benefit the fluctuation on stock prices.