why do you want to use textures and 3d? I'd prefere going with DDraw.
All you need is a backbuffer, a frontbuffer, and a blur-function. Then just do it like that:
1)roto-zoom backbuffer
2)blur backbuffer
3)draw to backbuffer
4)flip
5)jump back to 1)
should be working...the problem will be the blur which is very slow on high resolutions!
ciao...
...jens