The literature about K3 surfaces is extensive. However, I am not being succesfull to find anything related to the study of derivations and locally nilpotent derivations on these surfaces. What could be a reference for

1. a description of the derivations on these surfaces?
2. a description of the locally nilpotent derivations (if there exists) on these surfaces?
3. a description of the automorphism groups of these surfaces?
4. any condition for the group of automorphisms of these surfaces to be finite/finitely generated?