Always will have my lens hood on...flare or no flare heh.. For me it is not so much due to fear of flare but for the safety of my len and front element. As I do slung the camera sling over my shoulder and walk about and sometime very close to people who miht bump into it and there is also my clumsiness when I grab the camera or even lens when I find something nice to shoot and accidently touch my front glass and leave a smear on it. Agh...
And it also help to protect my lens when I get into tight places or just rounding a corner and especially if I have my longer telephoto lens on, I have ever knocked it against the corner wall or some object and the hood takes the main knock instead of my lens.
The only time it comes off is when I am using my wide angle lens and I am sure it might partially block the built-in flash.
Also comes in handy when I am changing lens fast. As the front glass can be quite close to the lens edge. When I take out my lens from the camera, i sit the lens on it's head resting on the hood while I then put another lens on the camera. Then place the back cover over the lens I took off my camera. If I am shooting from a fixed point, I would usually do that. Sit my 3 basic lens on it's head with the hood on of course and then just change around. So the hood serves another purpose for me