I actually turn my machine ON to clean the bobbin area/oil it. I can't see without that light...
If I'm changing the needle, I do leave the needle out until I'm done, but I don't remove it. I usually lift my foot onto the chair so that I can't accidentally press the foot. Maybe I need to start unplugging the foot so I don't have that to worry about. My bobbin runs on a separate motor (awesome during embroidery since I can wind a bobbin for my next color while it sews) so I can't use that tip.