Does general anesthesia have the same risks as with twilight?

Yes. The risks of any deep sedating agent and technique are generally the same. In twilight sleep the main concern is over-sedation and an inability to protect the airway. In general anesthesia the concern is sore throat from intubation, and waking up at the end of the case.
Risk. Is individualized to the patient and surgery. Both choices carry risks. General anesthesia is more invasive, but allows for greater control.
Slightly more. But either way the risk is extremely small. It's like asking if lightning is more likely to strike your house next week or the next two weeks. Twice the risk, right? But still near zero either way.