Personally, I think birds should fly as that is what they are known for. The only reason I would say clipping a bird's feathers is okay is if they are aggressive and fly to attack you and clipping their feathers helps to tame them, or if the bird has physical problems that prevent them from flying properly and when they do fly they crash into things and hurt themselves. Other than that I don't really see why you would clip a birds feathers. As for birds escaping through open doors or windows... You just need to be more vigilant and make sure everything is closed and secure. After all, it is your responsibility not the bird's. In my personal experience; All my lovebirds are unclipped except my stunted little baby. She cannot fly properly and when she does she crashes into walls and bangs her head on the roof and it was awful. So I clipped a few of her feathers, about three on each wing so she can still kinda fly around her cage but not hurt herself when she is out of her cage. My Amazon parrot was clipped when we bought her back in 2006 and just recently her feathers grew back in and I will not be clipping her again. I think flight is essential for a bird's physical and phycological health and they should be able to fly.