I agree with Jbaldwin. I think you will get poor resolution stars using a cubemap but if that doesn’t seem to be a problem, do whatever is easiest.
I did the camera following thing once for a light beam effect in the underwater gears3 level. Ended up doing it in the vertex shader, basically positioning the effect at 0,0,0 and adding camera position to the worldpositionoffset. Very simple, no tick cost, and you can still tweak the star size/tiling independently. Also had to make the bounds huge.