I agree with Simon's sentiments for question #1, and was actually going to pose the same question. Non-votes seem like they may poison the well mathematically, and counting them anyway seems to encourage a lack of participation at a time when miners really need to be very much involved. Since we're handing them even more control over the ecosystem with this BIP, it would be nice to ensure they (all miners) seriously consider their impact and role on a regular basis.

I'm curious why we couldn't/shouldn't simply drop the non-votes. (There may be a great reason that I can't think of, but it's eluding me... LOL)

That said, I don't see any issue with counting votes from outside of the range as the maximum/minimum accordingly (Simon's question #2). In fact, such votes would be very interesting (worthy of further discussion) if they begin to lean heavily in either direction.

V/r,
Oliver