I uninstalled the products that the download page told me to uninstall, but no, I don't think I uninstalled formbuilder 1, it wasn't listed as needing to be uninstalled, and I got the message stating that I was installing a product with the same name, and did I want to overwrite.
"Please note: CSS Form Builder 2 includes all the functionality of the older Validation Toolkit and Digital File Pro, as well as the current versions of Universal Email and HTML Editor. If you own any of these tools and it is currently installed, you will need to uninstall these extensions from the Adobe Extension Manager prior to installing CSS Form Builder 2. "
It hung both on trying to update a form created with the older version and on any new forms I tried to create.
It appears to be working now, but as you can see from my second post, it doesn't seem to be working correctly. If I uninstall it completely, to try a fresh reinstall, will I lose any custom templates and css that I've created?