This may seem a little convoluted, so bear with me...
My first question that came to mind in this meta-ish gray area was about suspension of disbelief when it came to specific audiences, as in:
When creating a sci-fi world/story/game for teenagers you can get a away with a bit more hand waving than you could with, say a sci-fi tale for those with physics majors... How much scientific accuracy is really necessary to make a world palatable?
Or perhaps more problematic in judging where to set the lines and veils of a world:
I'm thinking about creating a world that skirts the line between comic and disturbing horror, how far can I push the audience before it's too far?
These sorts of questions seem subjective, obviously, but I'm not sure if their too subjective to be answered... Though I suspect that they may boil down to poll questions where the real answers are found through community votes.