Hello kdiverdown,
Thanks for that info and choosing the Apple Support Communities. I know how important having your trackpad work with your iMac is to you!
If I understand correctly, you are unable to pair the trackpad with your iMac, even though your iMac does recognize the trackpad. Please follow the steps in this article in order to help resolve your issue:
If your Apple wireless mouse, keyboard, or trackpad aren't working as expected
Cheers!