Hi Friends,
Hey, I've found a few more tidbits of info about this snapping behavior with spirograph-made paths. I guess I'm not going to set up any SVG's for examination, at this time. I'm going to give petaIMG a little longer before I go for Firefox and Mediafire.
I've made probably hundreds of spirograms over the last couple of weeks (as I said, it captivates me!). But I just tonight noticed that not all of them are closed paths. Ok, here, I'll put up some PNG's, just for a visual.

Notice at the end of the hot pink arrow is the end of an open path. But the other spirogram is clearly closed. As a general rule, the more complex the spirogram, the more it's likely not to be a closed path. Although there certainly are very complex, closed-path spirograms.
Um, my snap settings are:
What snaps: Nodes
Snap to objects: Snap to nodes and Snap to paths
No snapping to segment intersections.
So here's what I've just observed:
-- Using a simple rect object, which has NOT been converted to a path, each of its corners snaps to the end node of the path on the left, the open path. But its side segments will not snap to the end node.
-- The rect also snaps to certain other areas in the path on the left. But I haven't yet determined what distinguishes the other areas, that might be causing them to snap. The path on the left has 1000 nodes, so I'm unclear why the rect's corners snap to the end node, possibly some other nodes, but certainly not all the nodes. I'm also not clear why the rect object, which contains no nodes, only snaps at the corners, where the nodes would be if it was converted to a path.
-- All sides and all corners of the same rect, will snap to every node and segment of the closed spirogram, on the right. I'm unclear why the segments of the rect can be snapped to the spirogram on the right, but not to the end node of the one on the left.
So that about covers the new facts I've just observed. I suppose if someone was interested enough, I could email the file to them, and they could upload it somewhere. But otherwise, I'm content to give petaIMG a little longer, for now.
[Edit -- Just figured out that the other area of the left spirogram which is being snapped to by the rect object is (duh!) the other end of the path. It's hard to see, in fact I can't see it at all without a good deal of zoom. And again, it's only the 4 corners of the rect that snap, its segments do not snap to these end nodes.]