Hi olimplus ,
Thanks for your post.
According to your post, Would you like to have the different forms for the different users (Author, Manager).
You can create the different content type for the different users.
1 copy the content type "user mini", add the others fields you like.
(copying "user mini", Because the fields of the "user mini" are necessary to create a user type.
2 In the "form action"(button "edit action field"), pay attention to choose the "Action mode" as user.
Hope that can help you.
Best regards