Questions for twitter bot application


Hi, I want to create an application that automatically posts images in eg guitar store accounts when a button is clicked.
The point is to have a service that stores can use and when they want to post new arrivals etc be able to upload photos to their accounts but we’d like to be able to do this using one application on twitter and have the users login once,give permissions and then they can use the consumer credentials using their own individual token credentials on a per client basis.

Can I create a twitter application that supports more than one user account connected to it for this automation?
Also I tried creating a dummy to figure out the web api calls and managed it but the dummy application cannot be found using Search.So I can only acquire the access token of the admin through the settings but I cannot subscribe a new user.

Is this perhaps a use case for xAuth?