Surprisingly, the cats leave the sub alone completely. I don't know if that is because it scares them or just because it isn't as interesting as it seems, at least not to them? (we have 3).
I've had that glass table in my living room for a few years and it hasn't been an issue, or I would have gotten rid of it
It is hard to tell from the pic, but there's about 2-1/2 to 3ft between the table and the speakers; the room is approximately 25x14 and the ceiling slopes up from what you see there to a peak about 20ft on the opposite end.