After creating a call flow the only way to test the call flow is to publish the call flow. The same goes for connector actions.

In order to make sure that all of the variables and other items are correct in a call flow you have to test by publishing.

After testing a web service might be moved from one server to another and the endpoint changes. That means that you have to create a new connector action to change the endpoint. Which also means changing the call flow and all of the variables to point to the new connector action.

This is a lot of work to not have configurable endpoints. Could this be a possible enhancement? 

Scott, I can certainly understand your frustration with the process, and we are in the process of a couple of efforts that should improve the overall process of creating actions and using them within call flows.  I don't want to get into specifics about upcoming features, but I will say that we have certainly looked at the pain points in this process and focused on addressing as many of them as possible.  

In the mean time there exists a potential workaround.  The custom bridge actions are currently referenced by name; if you were to delete the action and replace it with one with an identical name there would be no need to re-map variables within the call flow.  I realize this isn't exactly ideal, but it should suffice until some of the changes I previously mentioned start releasing over the coming months.  

(as with anything that involves a delete, please backup important items like configurations and test in a controlled environment before touching anything that is used in a production business process)