Question about steps to convert from Ubercart to Drupal Commerce After running into some discount functionality/module install issues with Ubercart for Drupal 7, my client has agreed to try Drupal Commerce. Do I need to completely remove everything related to Ubercart before Drupal Commerce can work, or can I unpublish the existing Ubercart content and disable the modules to allow my client to give it a test drive?

I see that there are some machine names that are the same from one to the other, which could pose a problem.
The two projects are incompatible because of the lack of name spacing in Drupal 7. Your best bet will be to completely delete all of the Ubercart related content and uninstall all of its modules. For obvious reasons, I'd recommend not doing this on your client's live site. Create a copy from a backup and perform your test / research in that.