Love the swing idea. Very cute, but as was said, I wouldn't want the supports made of a chewable material. One of my lard-butts would collapse it on himself sure-as-shooting. They're cute, but not necessarily the smartest little guys... I vote for wire to hang it just b/c it's less expensive and yet still tough enough for a chin and most small and medium parrots. (That and some of the bits of my scrap pack that won't handle a 5/16" hole would still take the 1/4" bit fine, so I could get more toy parts for my money. :thumbsup
Now, another new idea: A nice wide wood ledge, the size of a sleep'n ledge or a little bigger maybe, with a fleece 'tent' on top. Bolts into the ledge to hold the weight and a length of chain, wire, or fleece to attach to the cage or shelf above the ledge to hold the 'tent' up, but not take any weight. Since chins like to 1) Hide and 2) Cuddle on soft stuff, I'm sure a little chinny Pup Tent would make some fuzzball's day.
I could see it making a good 'nest' in a maternity cage if it's bolted onto the lowest level of wire, too. The kits would only have to hop an inch or two off the ground, but they'd be nice and sheltered without getting landed on. It could work for hedge hogs too, come to think of it. Any hedgie owners care to chime in with their expertise on that?
And, a 3rd idea that's not chinchilla related: I'm not extremely knowledgeable about birds, but since you've got a variety of woods to work with, would some of your larger pieces work for hollowing out as nests for small and medium cavity nesters (with or without the roof idea)? I've seen finch and canary houses made from coconut shells, which made me wonder what my (former) MiL's Alexandrian Ring Necks would do with a big old chunk of hollowed out Pecan or Yucca that they could destroy from the inside out.