They have a good body of work behind them-they have many years of experience in this field. This phrase is used for people in arts/people who write books/reports.
…where the principal actors aren’t required-a principal actor can be anyone with a speaking role on camera; however, it will depend on the nature of the production as to who counts as a principal actor.
…it doesn’t quite take the same toll on your body-something that takes a toll on your body ‘stresses’ the body and, over time, can damage muscle, joints etc.
CGI: computer generated imagery-computer generated effects in TV/film.
….doesn’t go into shards-piece of broken glass that typically has sharp edges.