Joomla front end map function gives a narrow map
This is caused because the system expects to find css and other files under the civicrm folder.  This folder does not exist in [joomla root]/components/com_civicrm.  You can solve this by creating a symlink as follows:
cd [joomla root]/components/com_civicrm

ln -s [joomla root]/administrator/components/com_civicrm/civicrm civicrm

I suppose it is possible the code will be changed so this is unnecessary or the installation process will create the symlink if it is not needed.