On my Eagle Embraers, the exit row shades must be open as well as 1A, for taxi, take-off and landing (critical phases of flight.) In the event of an emergency evacuation...the flight attendant has to assess the conditions outdoors, through the 1A window, prior to opening the passenger entry door. We look for fire, water, debris...anything that would make this an unsafe exit. The exit row shades must be be open for the same reason.

The seatbacks must be upright to allow the passengers behind you (or those that may end up behind you if a fuselage rolls over) more room to exit into the aisle. This is the same reason why your carry-ons must be ALL the way under the seat in front of you...to give you a clear row to get out of the plane.