The package name is kind of misleading in a way, well...I mean it should probably be reworded. It’s the name of the interface, e.g.:
By default it’s setup like this:
You can put whatever you want in there I suppose, or even nothing at all, Magento will revert to the default interface though if it can’t find anything. But if you haven’t created a new interface directory, then there’s no point.
The only way to change the URL is to move Magento to a different sub-directory. You should be able to rename the directory, but make sure you update the paths in the backend of Magento first. Also a good idea to clear your sessions/cache directory out too. Then rename it.