No, the order won't matter (optically, ie).

I don't know what you mean by "views". Perhaps as ND filters?
The CPL should be about a stop.

About reflections: PLs (whether Circular or Linear) cut reflections where the reflected
light is itself polarised. In the case of running water, the effect may not be as pronounced
during the exposure time involved because the angle of the reflected light
from the water will be always changing.

It sounds an interesting shot to try, though, and I look forward to your results.