I took it apart so you don't have to (unless you want to of course....[;)])
I like your laser mod. :)
Unfortunately the optics appear to be too narrowband to get a blu-ray laser to give any visiable amount of blue, so a full-colour laser hack would probably not be possible.. :-)
Actually, the blue path only sees a mirror, then a green-reflect dichroic, then a red-pass dichroic. All the filter lines should be well away from a blue laser line, and it should pass fine. The problem might be the collimator lens directly in front of the LED. It is designed to collect a very wide angle from the LED and collimate it to pass through the dichroics and fly-eye. If the laser is already well-collimated (most likely is), then these lenses are probably doing just the opposite and focusing/spreading the beam so much that much of the light is lost. Try removing the collimator lens. You may have to put a weak lens in its' place to spread the beam far enough to fill the DMD.
I will warn you, if you get ill from viewing speckle, have a bucket nearby.
Mike Davis