ditto on the Wilton fondant issue.
I have wondered numerous times about the non-toxic question, and although I don't use any Crayola markers - I would be willing to bet they are no more dangerous than a marker with edible colors.
Some of the dyes approved for consumption by the USDA - like Red Dye #6, were later found to cause problems in humans. Cancer, I think, but don't quote me on that.
I'm pretty sure the 'edible' ones are not nutritious in any sense, and as such, are probably no different from the non-toxic ones.
a million years ago - I was studying marketing and it was interesting to find that a number of big 'brand names' also sell their identical product under other names. For instance, Loreal products are often Clinique brand, just repackaged. they can sell to more markets that way. Kraft sells its cheese under different store-brand names sometimes.
I wouldn't be surprised to find some edible and non-toxic markers to have the identical ingredients.
but - that's just my thoughts. I have no proof.