All right, the crash info is kind of generic, unfortunately.
Let’s try this test now, when you get a spare moment. Reboot the Mac using safe mode, and attempt to use Scapple without running anything else first. This will be slow, and not very useful—but what it will help us learn is whether there are external factors involved, such a driver or even a program you tend to use in the background (e.g. a sync tool or clipboard helper).
If it runs in safe mode, then reboot normally, and this time right after you confirm your password to log in, hold down the Shift key until you are fully logged in. This is a bit like safe mode, but it allows drivers and other system-wide tools, while inhibiting tools you run yourself, or that start automatically or run in the background. Again the idea is to run Scapple before launching anything else. You should only have Finder and Scapple running.