No. Every medication can be reversed or anesthesia lighten. Blood pressure and all hemodynamic parameters are monitored continuously.

Possible? Yes, like every drug, anesthesia also has a safety profile, if you overdose the patient there is a danger of causing harm to patients and / or death, and that is why it can only be administered by a licensed professional trained to do Anesthesia.
In reality death in a healthy patient or in a patient with well-controlled medical conditions is extremely rare.