I have been fighting to get workflow manager installed and running on my dev server for about two weeks, installing/uninstalling/reinstalling over an over again. I was FINALLY able to get it working by:
Leaving the WFM farm
Completely uninstalling WFM and the CU's
Deleting the databases
Deleting the workflow proxy service in CA (important)
Restarting the server
Reinstalling the thing all over again.
The only problem now is that I can't figure out how to uninstall the Workflow Manager Client. It doesn't exist in Add/remove programs and it isn't supposedly getting removed when I uninstall WFM. I know this because when I went to reinstall WFM through web platform 4.6, the client showed as already being installed. The main problem I am having is I can't create 2013 workflows in SPD. I even tried downloading the actual Workflow Manager Client executable thinking I could manually install it, but it opens web platform 4.6.
WFM does not clean up after itself very well when you uninstall it, and believe me, if you leave any piece of it on the server you will have problems when you go to reinstall.
Very aggravating. If anyone can tell me how to blow just the client piece out, I would greatly appreciate it.