All window shades should be open during takeoff and landing. During cruise, the passenger next to the window should decide positioning while being courteous to other passengers during movies and/or on redeyes.

Exit rows should be no different, except that perhaps the FAs should be a bit more vigilent in enforcing the window shades open for takeoff and landing policy.

This is not (necessarily) official policy, but it should be

I can guarantee having the shades open is safer than having them closed. And no, you can't be counted on to open them to check for danger before an evacuation...just like you can't be counted on to raise your tray table or seat back, remember how to unbuckle an unfamiliar seat belt (not at all kidding), or remember to put your own oxygen mask on before assisting others.

People who sit in exit rows for the extra leg-room should realize that the extra leg-room comes with the price of being responsible for potentially helping to save the lives of their fellow passengers.