Unfortunately it still means you have to focus on making interviews.
You can always overcome this by purchasing several copies of your reward objects to stack and amplify their mood effects. The Author Branch is for Sims who want to focus on more on writing books.
When you will become a Bestselling Author 9 A you will have to learn the 10th level of Writing. You also can use an interaction called "Make a biographical interview".
You need to keep being Inspired. To reach the next level in this branch your sim must raise their Writing skill to level seven and Charisma to level two. The more books you will write, the faster you will earn needed amount of Simoleons and these royalties will also be useful on one of the future ranks.