Anna Chan writes: "We're all fine. Everything's fine."But everything was not fine.The horror of what the Seattle Grace doctors went through on the "Grey's Anatomy" season finale reverberated through Thursday night's premiere. How could it not? Their friends and colleagues were shot and killed before their eyes. And every time one of the shocking scenes replayed on the small screen, it was hard not to feel the jolt again.No wonder Meredith,...