Whats more dangerous for a kid, to go under general anesthesia or to be on conscious sedation?

It depends. It is hard to say without knowing more information - the age and size of the child, and their other health problems, as well as the type and duration of surgery being performed. Both general anesthesia and conscious sedation carry risks, no matter what. But both can be performed safely by experienced anesthesia practitioners as well. .
Both have . Risks and benefits. Discuss your options with the surgeon and anesthesiologist and they will give you their best recommendations.