Bryan,
We've been told by Axiom that you can drown the Algonquins in a swimming pool and all you have to do is remove a driver and let the water drain out. So it appears that water isn't a concern for longevity. Now having said that, they probably would sound terrible if they are filled with water. I am sure you don't want to go up there and be emptying them all the time. In retrospect, it would have been a heck of an idea to have some strategically placed drain holes in the enclosure and perhaps a port that could be rotated to orient the internal tube.
I can't answer your question about the bolts or stability as I have never seen them up close. I personally wouldn't want a loose piece of plastic in my speaker though.
Looking forward to meeting you at the get-together.
