1) How many VX were made?

I dont know how many were made total but a little over 4000 were exported to the U.S. between 1999 and 2001.

2) What is the difference between a Dragon, and a regular VX? What makes it a Dragon?
Dragon refers to the color exterior of the VX - Dragon Mica Green

3) Reguardless of mileage - what is the most desired year of this model?
It depends on your tastes... 99's came with 16" wheels, 00-01 came with 18" wheels; 00-01 models have auto climate control; 99 models came iwith exterior color choices of astral silver, ironman pkg.Victory white, and Ebony with red/blk interior. Beginning with 00 models, Isuzu introduced new exterior colors of Proton yellow, Dragon Green Mica, Foxfire Red Mica and Kaiser Silver with the added choice of Grey/Blk interior.