Yes it is safe for human consumption several brands of soft drink from guarana extract are sold in Brazil. they consume the third-largest amount of soft drinks in the world
No. Remember it is what is left after digestion, it is full of Ecoli bacteria and other germs you don't want to put in your mouth.
The short answer is "Yes". It will likely give you diarrhea and should not be ingested by people who have heart problems or renal problems.
No. It is, afterall, the waste material that your body decided not to use. In addition to that, it is full of bacteria and could contain pathogens.
=D
Only for Vampires.