Possible Clues:

• An old rebel musician snubs American RA perhaps
• Scholar revised a manic idea about carbon
• I’m a nice cad, a perverted RA member, perhaps
• Institutional scholar
• Eg, member of the RA
• Distinguished scholar developed a manic idea about the speed of light
• Distinguished scholar
• An RA, perhaps
• Recognised artist half-hidden by shrub, note
• Teaching scholar