By default all the users have access to openshift project in the cluster, our default installation script
usually creates a set of standard images in there . This way all the users have access to them
and you could leverage this. Other option is to create your own project that will be available to all users,
iow. you need to to give them all that access.
As for the auto rebuilds, this depends on the BuildConfig author to create an Image Change Trigger ,
which are created for you automatically when creating an application either using CLI or the web console.
But they can still be turned off by the author afterwards.