Yes, or alternatively via Apps (enable re-install default in its Settings), then from installed apps do a reinstall default, change the name etc.
Yes, because the layers wind up being shared between the two instances. Alternatively, you can "tag" the apps to use one of the available tags (click the icon and then select more info to see what tags are available), but then at that point, you're forcing the app to stay on a specific version, so you lose updates.