Hello Adam,
If the Administration tab is not appearing, that usually means there is an issue in the way the <identity> elements are configured. In this basic setup, we are not connecting the geoportal to any user directory tree; we are configured just one administrative user. In the <identity> element, the steps are to uncomment the <simpleAdapter> section, and comment out the <ldapAdapter> section. Also within that <ldapAdapter> section, you will have to uncomment the <metadataManagementGroup> section. Will you confirm that you've made these changes? If you want a second set of eyes, feel free to paste in that whole <identity> section and we can doublecheck.
Christine