Um. I'd say no since I generally assume that an undead must have been organic at some point to be 'the living dead'. A warforged is a metal contruct, so I'd say that it cannot be undead.
..and I am having brain issues with the template system for some reason. Rather than making one for me (although I would happily accept that too), can someone talk me through the process?
Oh...and can there be such a thing as undead Warforged?
Allen
I believe if you applied all of these templates together, you're going to end up with some weird gestalt of a foe that the PCs cannot conquer, even at 30th level. Take a look at the level requirements...
In essence, I'd limit yourself to two templates max (and that may even be pushing it). Just take the standard monster/foe from the MM, and add everything up cumulatively.