For those who are still running into this problem, it took me two tries with the following steps:
- Uninstall 1Password (Settings... > Manage Extensions... > Uninstall)
- Clear the cache (Develop > Empty Cache > Empty)
- Quit Orion
- Run Orion
- Install 1Password (Popular Extensions... > Get > Add)
- Clear the cache (Develop > Empty Cache > Empty)
- Quit Orion
- Run Orion
Since 1Password was still crashing after I did this once, I ran through it a second time while documenting the precise steps I was taking to write this response. After doing it the second time, 1Password hasn't crashed. It still doesn't work on every site (ally.com, for example), but at least it's usable on some!