About importing journals in Outlook 2007 to Outlook Customer Manager, it’s not feasible to do that. Journal feature doesn’t exist in Outlook Customer Manager. If you want this feature, we recommend that you vote for the feedback via this link:
About the Timeline entries, do you mean the emails communication with the contacts? If yes, based on my experience, it’s not feasible to delete it. Also, it’s an expected behavior that it will automatically appears in Outlook Custom Manager once you receive an email from this contact.
About adding tasks, may I know how you add the tasks? When you open the Outlook Customer Manager in the Outlook client, Select New task in the main interface and you will be able to add a new task. The task will automatically add to the Task list and everyone will be able to see the task.
Saying Post, you can add the hyperlink to the Post and it will show in the contact details. Meanwhile, since we need to add a post to a specific contact, it’s not feasible to add the post to multiple users. You need to manually add them one by one.