Don't know any kids really, but from experience, I was too scared of the Penguin to see BR in the theater. I was seven. A year later, by the time it came out on video, my mom got me the video and I loved it, though I couldn't look when he bites the guy's nose off, or at Shreck's crispy corpse.
But I don't even think it's the characters and images themselves that scared me, but the dark tone, the mysteriousness of it. Hell, even movie Shredder kinda scared me, while I had no problem with the cartoon.
And The Crow bored the hell out of me. I was a stupid kid.