If the URLSegment of a page is "home/" I want to:

1.) prevent the page from being deleted
2.) prevent the URLSegment from being changed to anything besides "home/"

This is how I setup my homepage so it prevents renaming URLSegment, prevents deleting by non admins and force to be the first page in the SiteTree.

<?php

class HomePage extends Page{

	static $icon = 'axyrpack/images/icons/home';
	
	static $singular_name 	= 'HomePage';
	static $plural_name 	= 'HomePages';
	
	function canCreate() {
		return !DataObject::get_one($this->class);
	}
	
	function canDelete() {	
		return Permission::check("ADMIN");
	}

	function populateDefaults(){ 
		parent::populateDefaults(); 
	}  
	
	function onBeforeWrite () {
		parent::onBeforeWrite();
		if($this->ID){
			$this->ParentID			= 0;
			$this->Sort 			= 0;
			if(Object::has_extension('SiteTree','Translatable') && $this->Locale != Translatable::default_locale()) {
				$parts = explode('_',$this->Locale);
				$this->URLSegment 		= 'home-'.$parts[0];
			} else {
				$this->URLSegment 		= 'home';	
			}
		}
	}
	
	function getCMSFields() {
		$fields = parent::getCMSFields();
		$fields->addFieldToTab("Root.Content.Metadata",new HiddenField('ClassName', 'ClassName'));
		$fields->addFieldToTab("Root.Content.Metadata",new HiddenField('URLSegment', 'URLSegment'));
		$fields->removeFieldsFromTab("Root.Content.Metadata", array('URL'));
		return $fields;	
	}
}

class HomePage_Controller extends Page_Controller {
	
	function init(){
		parent::init();	
	}	
}

Thank you for this solution. Works perfect.