Actually all of those are physically more dangerous than LSD... LSD is physically the safest psychedelic. Iboga is far from safe... it's actually quite dangerous as psychedelics go. The iboga clinics, the responsible ones anyway, ask for a full physical exam and will refuse treatment to people who are not healthy enough, particularly in the heart.
Natural does not necessarily mean safer or better.
Mentally speaking, all psychedelics carry a risk of unlocking latent mental conditions such as schizophrenia, as do stimulants, especially amphetamines. If I were you, I'd stay away to be safe. But like others have said, there's no way to know for sure.