All good points, Ath - and made considerably more succinctly and intelligently than I could have managed. That Traviss has been a bit (how big a bit depends on your point of view) of a fool in engaging with fans in the way she has is inescapable. To what extent that colours your view of her work is likely to depend on things like how closely you identify with it and the wider body of Star Wars literature of which it's a part.
Despite Barthes' essay (which does have some validity - and yet is also quite problematic in its own way), the concept of the author isn't going to go away any time soon and the internet has, as Ath's rightly said, really divided the line between the 'author' as an originator of creative works and the 'author' as a fallible and probably quite annoying human being. The internet tests the premise that "there is nothing outside the text" to destruction - because, quite frankly, there's a heck of a lot outside the text and you'll find it plastered handily all over the net. That said, we should perhaps be a bit careful about turning to external sources for interpretative help when it comes to reading any given text. Just because an author states an aim doesn't mean he or she manages to achieve it. Sometimes, they achieve something quite different (yeah, Milton, I'm looking at
you), due to the slipperiness of language and its social/historical/cultural contingency. Sometimes the text stands apart from its author for a variety of reasons. Whether this is the case for Traviss, remains to be seen, but I am genuinely intrigued to see for myself. Just don't expect it to happen any time soon!

That distinction between the human being producing the work and the work itself remains the same throughout literature. I love Shelley as a poet, but it's impossible to ignore that he was a pretty crap human being. His treatment of women, for a start, was pretty awful and, like a lot of creative types, his narcissism is pretty unpalatable, too.
The thing about 'soapboxing' (which I take to refer to the practice of direct authorial interventions in the text aimed reasonably pointedly at the reader in order to hammer home a wider cultural/social/political point) is that it becomes more glaringly obvious when you don't agree with the point being made, and thus it's regarded almost wholly negatively. The worst thing that can be said about it, I think, is that it runs the risk of jarring the reader out of the story.
Going back to Hardy again, his authorial intervention after Tess' rape in
Tess of the D'Urbervilles - which effectively amounts to having a pop at God ("Where were you, huh?" - not, I should point out, a direct quotation) - didn't offend me so much for its atheism (if I got offended by atheists I'd end up having a very limited number of people to talk to) but for its pulling me out of the narrative a bit - not completely, but enough for me to notice what he was doing. And, given that the rest of the chapter was written with Hardy's customary skill, sensitivity and sympathy for his central character, it was all a bit unnecessary.
All of which is taking us a bit farther away from the topic, for which I apologise.
Bellarius, thank you for your earlier post, btw. I feel your pain - although, not being a big Star Wars fan, I can't really share in it.

Take care, good people!
JDD