To Dream In the Cities of Sorrow is 100% canon, just like the trilogies he outlined (yes he actually did say that those were canon), and the Shadow Within is 90% canon (though I'm not sure which 10% isn't).
The passage in Armies of Light and Dark (thanks for clearing that up, I get the titles screwed up occasionally), states that the ship Lou found was similar to the one that had been on ISN during Season 2-3, but far smaller and not exactly the same in design, hence it's a good bet that it's a Spitfire. We also know from the DC Comic run, the spitfires had pilots (though these aliens didn't appear to be Drakh from what I remember).
Using the Warlock-class Destroyer as an example of 'mastery of shadow tech integration' is a bit misleading. We have to remember that the Warlocks were supposed to receive Shadow bio-armor which really is what gave the Omega-X it's appearance. The Warlock itself had some Shadow programming in its computers, though I hardly think that counts.
Still, it doesn't seem to make any sense that the Drakh would not base their tech more on what their masters had. I mean, is there a reason why Drakh vessels haven't been equipped with the far superior Shadow bio-armor (assuming that Drakh vessesls are sporting bio armor of their own, which I thought they were), like EarthForce tried to during the Clarke Administration and Black Ops dealing with the Shadow Hybrid?
Also, does anyone know of any other races that served the Shadows other than the Drakh, Zener, SODs, and Wurt (whatever the hell they are. mentioned in Technomage trilogy).