Your best bet for an answer is an interview that was in the back of some copies of The Unifying Force and possibly some copies of the Vector Prime ebook: Star Wars: New Jedi Order Round-Robin Interview, featuring:
- Shelly Shapiro, Editorial Director, Del Rey Books
- Sue Rostoni, Managing Editor, Lucasfilm
- Lucy Wilson, Director of Publishing, Lucasfilm
- James Luceno, Author
This interview usually comes with the Yuuzhan Vong entry from the New Jedi Order Bible that the authors used to keep continuity straight. I did not see much behind-the-scenes details in there, but it may be worth checking out.
Here are some excerpts that hopefully answer your questions. Note that there are spoilers below for the New Jedi Order series.
On the origin of the Yuuzhan Vong:
DR: I've heard that the name Yuuzhan Vong came from a
restaurant menu during an early editorial powwow. Any
truth to that?
LW: You bet. Yuuzhan Vong, as well as many other brilliant
ideas over the course of history, came from food.
SS: Lucy and some of us Del Rey people were eating lunch
at a wonderful French-Thai restaurant called Vong here
in New York City. I suggested using Vong for the alien invaders.
But we wanted something more, and perusing
the menu, I came across their list of teas, which included
a mention of the "Yunan region." We tossed around ideas
and came up with Yunan Vong. We added an extra n,
making it Yunnan Vong. But a week or so later, we decided
that we wanted it to sound more alien and less
Asian, so we changed it first to Yuzzan Vong, then to
Yuzhan Vong, and finally settled on Yuuzhan Vong.
On the role of George Lucas:
DR: How much of a role did George Lucas play in shaping
the series?
LW: George Lucas has been involved in all of the spin-off
Star Wars publishing, but only on big concepts or plot
points. The initial five-year NJO plot outline and early
thoughts on who might die were sent to him in the form
of a Q&A memo and subsequently discussed by phone.
SS: I would characterize his role as limited but important.
He's the one who said the alien invaders could not be
dark side Force-users, that we couldn't kill
Luke
, that we
had to kill
Anakin
instead of
Jacen
(we had originally
planned it the other way around). Other than that, he occasionally
answered some basic questions for us, but
that was rare. Mostly he leaves the books to his licensing
people, trusting them to get it right.
On force immunity:
DR: I'm still not sure I understand how the Vong can be immune
to the Force.
SS: Me, neither. They're not exactly "immune" to the
Force, though-they just can't be "sensed" through the
Force.
SR: This is all explained in The Unifying Force, never fear!
JL: Our original idea was to give the Yuuzhan Vong dark side
powers and test the Jedi in a way we imagined the Republic-
era Jedi had been tested. When that proved unworkable,
we began to wrestle with the idea of making
the Vong immune to the Force, which of course led to
countless discussions about midichlorians and the possibility
that the Force was peculiar to the Star Wars galaxy.
All this was admittedly muddled, and almost every
writer had a slightly different take on the notion of "immunity."
The basic idea was that the Vong could not be
perceived through the Force and therefore were not susceptible
to certain actions by the Jedi: very much in the
same way that Toydarians, Hutts, and other species are
immune to Force suggestion, and Tim Zahn's ysalamiri
are capable of repulsing the Force. At the conclusion of
the NJO . . . but perhaps I should leave that discovery to
readers!
On bio-tech:
DR: Who came up with the idea of a biologically based technology
and a culture with a fanatical aversion to machine
technology and a value system and
sadomasochistic theology based on conquest, violence,
sacrifice, and pain?
SS: Bob Salvatore invented the biotech concept, which we
liked. We built on that to come up with the fanatical
aversion to machine technology. We kind of liked the
flip-flopping of the way it had been in the original
movies: there, the high tech was mostly in the hands of
the bad guys, while the good guys wore homespun and
seemed much more low tech. So here it's the reverse: the
good guys are high tech, and the bad guys seem more
low tech, although they're really just "different tech."
The sadomasochistic theology was not planned, and
while we tried to pull back on it, not stress it so much (we
really wanted it only to be the extra-fanatical Domain
Shai-of which Shedao Shai was a part), it took on a life
of its own.
JL: the time of the first story conference, I had just returned
from an extended trip in Mexico and Guatemala, and
during the brainstorming sessions, Del Rey editor Steve
Saffel wondered aloud if the Aztecs or Maya might serve
as models for the Vong. We began to work with this by
imagining a kind of organic-tech Aztec society with a
pantheon of gods, rituals of automutilation, a rigid caste
system, and a hatred of machines.
We weren't out to reinvent the wheel. We were simply
trying to come up with villains who had the potential to
become as interesting as Palpatine and Darth Vader. Our
original conception of the Yuuzhan Vong expanded in all
directions after Bob Salvatore, working from scant
notes, gave them an actual look and created examples of
their wondrous biotech. Mike Stackpole was largely responsible
for the system of ranks, and we borrowed
heavily from Central American mythology in creating
the pantheon of gods. Kathy Tyers and Greg Keyes contributed
immensely to this process, further defining the
warrior and shaper castes and in enlarging the Yuuzhan
Vong menagerie of creatures. Yuuzhan Vong words and
phrases accrued as the series progressed.