The big danger with 'bad acid' is getting an RC, particularly a DOx, and especially if you also happen to decide to take several hits of "acid" at once which is perfectly safe with LSD but not with many other drugs. Even at the intended dose, a DOx, which from what I hear is a much longer, more stimulating version of a 2C trip for the most part, would be unsettling to say the least if one were expecting 12 hours tops of a low dose LSD trip.
Assuming what you eat is either acid or at worst blank paper, the only real dangers are psychological. There's no such thing as a way to trip with absolutely no risk of even psychological 'damage' but, in my opinion at least, any damage they cause can be undone with proper analysis. They seem to bring unconscious activity, including various little neurotic quirks we all have, into conscious focus, sometimes for the first time - some people find this very difficult to deal with. I've never had a trip leave me with any difficult state of mind that persisted longer than the drug's effects. Virtually every dose of each psychedelic compound I have tried has been a positive experience, for me at least. I know people who are less sure that psychedelics were entirely positive for them but I doubt any would take any of it back given the choice. If a psychedelic experience is intense enough to be that negative, it's usually also a valuable experience if you're willing to learn from it.
FWIW, having now tried the 2Cs, I don't think any of the tabs I've tried were anything but acid. If any of them was an RC - hot damn, I wish I could figure out which one it was!
