I figured out the problem I was having with OpenShift.
To put it simply, I didn't pay enough attention.
For reference, when moving an existing TurboGears app to OpenShift, make sure you add the changes in config/app_cfg.py
As soon as I saw that, I felt really silly for missing it. I was so sure that I had gotten all the relevant changes, but apparently I somehow missed this file.
More detailed directions coming soon.