I checked for rear wheel warpage, there is no substantial warpage. I haven't checked the front for warpage, though.
The rear wheel was out of alignment, though. Using a straightedge, the right-hand side had around maybe 1-1/4 inch between board and tire, and the left-hand side around 1/8 inch. Is that enough to cause bizarre handling/instability? I do know that it helped alleviate the belt squeak. I moved the bike around and then propped it up and ran it with the tire off the ground, and then I used a wooden block to push the belt over a bit. It still sets against, or nearly against the pulley sidewall, but it's better than it was. The spinning resistance still seems more than it was the last time I checked the rear brake. Maybe I need one of those rubber shims somebody keeps talking about. However, the pulley does not seem to have a lot of play in that direction. Sometimes I wonder about frame warpage

. I know somebody here has that issue. He says he can make the rear wheel track but not the belt

. On the other hand, my crash wasn't extremely violent; it was at a moderately low speed. Maybe it just got knocked out of alignment? I hope so.

I remember looking at the swingarm marks a day or two ago, and I thought they looked the same, so I don't know. I doubt it had much of a problem when I bought it. Who knows?
Here's a mystery to solve: My odometer a day or two ago read 16691 miles. I haven't ridden it very much since the crash. Can anyone figure out the mystery?