can i install an app on one mac, and move it to another mac without installing it it on the other mac and not having to enter the administrator password?
For apps that are a drag and drop install (ie. you drag them from a disk image to your Apps folder), you can copy them from one Mac to another no problem. Preferences won't be carried over unless you copy the preferences file too. You'd have to type an administrator password if you're logged in as a standard user, but if you're logged in as an administrator, you won't need to.