Currently the Journal list up all activities of a user or group. I would like to have a journal of an entity. 

For example, the journal has already event journal types: "Created Event, Attending Event". In that case, I would like to list the activities for a certain event. If I comment on Cathal is attending event DotNetNuke Open World, this comment should be seen within Cathal's journal and the event journal.

Is this possible? IMHO this would only require just a fork to the Journal module (and custom Journal Types).