It is possible to use fewer views. There is also room to make it faster, with functions that have been added since then in A8 (such as view_check). If you want to use just the widest view, it's mostly be just the same as the original shadowmapping.c example with a couple of changes.
If I were you, I'd use:
return tex2D(TexSampler,inTex) * min(fShadow, fDiffuse);
This will make a smooth transition from the cast shadow to the diffuse lighting. Then, if you need the shadow to be less dark, change fDark near the beginning of the .fx file.
The way it is set up, you'll need to add the shadow stuff into each different material manually if you want them to receive shadows.
Out of curiosity, what are your system specs? And what kind of framerate are you getting?
Jibb