Yes, you can restrict the elements (input, styles, formats) to the users who are using the (F) CKEditor. In my case I used CKEditor for SharePoint 2010. Here’s some quick tips / howto’s regarding restriction with CKEditor:

#Delete those nasty plugins, especially the one defining the current context
config.removePlugins = ‘elementspath’;

#Force the Language
config.defaultLanguage = ‘nl’;

#Disable the option to collapse the editor, users only get lost
config.toolbarCanCollapse = false ;

#Dis or enable the resizing of the editor
config.resize_enabled = true;

#Auto Start SCAYT Spellchecker
config.scayt_autoStartup = true;

#Force spellcheck language
config.scayt_sLang = ‘nl_NL’;

#Only allow the tags P and H2 to be used
config.format_tags = ‘p;h2′;

# Remove any other Format
config.removeFormatTags = ‘b,big,code,del,dfn,em,font,i,ins,kbd’;

#Remove advanced dialogs
config.removeDialogTabs = ‘link:advanced’;

#Restrict special characters
config.specialChars =['!','"','%','&',"'",'(',')','*','+','-','.','/',':',';','','=','','?','@','^','_','`','{','|','}','~',"€", "‘", "’", "“", "”", "–", "—","©","®","À", "Á", "Â", "Ä", "È", "É", "Ê", "Ë", "Ì", "Í", "Ï","Ò", "Ó", "Ô", "Õ", "Ö",  "Ù", "Ú", "Û", "Ü","à", "á", "â", "ä", "è", "é", "ê", "ë", "ì", "í", "ï", "ò", "ó", "ô", "õ", "ö", "÷", "ù", "ú", "û", "ü", "‚", "‛", "„", "™"];