It is possible configuring rights for editing Maintenancejournal from within objectproperties of "Infrastructure Services".
Is there a possibility editing these rights from within user and group definitions at "User and groups"?
No, in Users and groups all access rights are related to global things - e.g. ability to edit server actions - this is not related to any specific node. But things related to nodes and other objects - ability to modify configuration, edit comments and edit maintenance journal are set in the object tree - this way you can limit users to access only some nodes which is typically needed.