1cm burns are too big. From my online research, they should measure no larger than 5mm. The surface area of a 5mm burn is 19.6mm squared, and the surface area of a 10mm burn is a whooping 78.5mm squared!! That's a fourfold increase.
Did you fill your 1cm burns completely with Kambo? If you did, you may have effectively been doing an 8-dot dose, rather than the 2-dot dose you were aiming for.
Also, yes, the yellow in your vomit is from bile. This is an extract from Giovanni's paper where he is quoting scientific research:
"So far, researchers have found nine bio-active peptides that have a potent effect on the gastrointestinal muscles, gastric and pancreatic secretions, blood circulation, and on the stimulation of the adrenal cortex and pituitary gland."
It therefore seems very likely that when people vomit on Kambo, they don't simply vomit the contents of their stomachs, but also vomit the contents of their intestines, specifically the duodenum. If you then shit as well, it is a complete flush from both ends! I'm guessing that's another reason why drinking water is so important - it not only stops the pain of dry heaving but it also helps to flush out your intestines as you vomit and shit out the watery fluid.