One thing I didn't mention before, which governs my choices somewhat, is that I also think that it is good for a child's imagination to have powerful imagery lurking down in the subconscious. Along these lines, for example, my son loves the movie "War of the Worlds" (this is a good example of something I let him watch with hefty doses of censorship) and has for some time now. Just because something has elements of the strange, powerful, macabre, etc. doesn't mean it's necessarily bad for children in my opinion-- in fact the stranger the better, in my view, as long as it's still reasonably near the comfort zone of the kid.
I actually agree with you here. I would love my DD to see Spirited Away--I love it, and I think she would too. It's possible that it would be okay...I should review the plot. Scary isn't the issue as much as things featuring cruelty to sympathetic characters or tragic parental death (so weirdly common).
I'm more willing to test something questionable if I think it's worthwhile artistically.
I figure he will let me know if he can't watch it comfortably
This may be the issue, really. Some kids seem to know this instinctively. DS will ask me to turn "scary" (we're talking a tense episode of Super Why here) things off fairly regularly. DD will see it through because she's interested and THEN be distressed afterwards. DS is generally a lot more self-aware than his sister, so this makes sense.
