Perhaps note that although those attending the party will not eat or drink (other than alcohol), they may be forced to do so by someone else without protest. If someone can think of a good way of demonstrating it, allow the "spore" method of reproduction to come into effect on those attending a party. Also with a good explanation for why, allow thick dust to knock those out attending a party (especially rock dust). Needs a better description of idleness, since that isn't what would be immediately observed. Those who admire Planepacked should call it by that name or something similar, immediately know it. Describe it so that "admiration" doesn't effect party; have that effect all those idling in its area equally, and perhaps better define the area (either the entire facility it's in or about the size of an embark tile).
On the drawbridge, you might explain it as erosion and a landslide causing a lowered drawbridge rest against the ground, then the drawbridge being raised, and those present discovering Planepacked. Those there would assume (delude?) it was revealed during the landslide, then proceed to move it to a place they can look at it more often (probably with heavy machinery) and subsequently have a party that brings the Foundations attention. The drawbridge could also be collected by the Foundation, and create more objects in the future, like lots and lots of rock of assorted types.