Kinda what I figured, then - I suppose it would have been a real pain to redo everything to work off the fragment shader! Thankfully, since mine is OOP, it's easy to slip code into several different parts and obscure it so it appears to be going to one location - I'll just use the fragment shader. I won't be able to add in a lot of dynamic pixel shader functionality anyway, since Adobe has kindly chosen (queue facepalm)
assembly as the main means to address your video card from Flash
As for the warp, I'm not sure I'll be able to pass it into the shaders using a matrix since the calculation is dependent on the uv coordinate being altered... I was thinking I'd pass in the warp settings on one of the constant registers and then alter the zoom/rot/rot center/dx/dy/sx/sy matrix once the uv coordinates become available (fragment shader).