Welcome to the forum!
Yes. Most people can learn surgery. The hardest things about surgery are knowing when to perform surgery on a patient, how to manage complications, how to deal with surprises during the case, and how to manage the patient as a whole patient.
Yes. There are some people who lack the manual dexterity/fine motor skills to perform surgery; however, these are few, and according to Dr. Nerad (Oculoplastics surgeon at Iowa), in his 20+ years of teaching, he has yet to encounter a resident that he cannot teach. 😉