Lit Which material does Lucenos' Plagueis reference? Also a question about Outbound Flight

I agree with your way of reading that sources in a certain ranking line, whereas IMHO your last two cited examples prove the contrary to your above mentioned words:

The "Bloodlines"-Comic which is devoted to the fate of Vidar Kim's Jedi-Son Ronhar, is a continuation of one loose end of the DP-novel. This comic would make not half of its sense without having read the Plagueis-novel before. And (please correct me if I should be wrong) there is no other detailed source to give us more about Vidar Kim than the DP-novel.

A bit different it is for the comic "The Yinchorri Uprising". It is nice to watch and read the comic, but its important prelude comes ahead in Luceno's novel. While reading that passage in the DP-novel, where the events of the Yinchorri-crisis are touched, I felt strongly that there must be a more detailed source worth to explore. I would say that for the "Yinchorri Uprising" it doesn't matter what to read first.

I for myself can say that without the Darth Plagueis-novel, I never would have tended myself to these two comics extending and deepening Luceno's novel that well. And I didn't regret to have chosen that reading line.