Firefox history

So, I wanted to block the history of firefox to forbid the user to empty it.

1. I had to remove Tools > Clear Recent History by putting the following in the profile’s userChrome.css file :
   #sanitizeItem { display: none !important; }
2. I had to remove Tools > Privacy > History :
   #historyGroup { display: none !important; }
3. I had to remove the details in Clear Private Data :
   #detailsExpanderWrapper { display: none !important; }
#detailsExpanderWrapper + #itemList { display: none !important; }
4. I had to remove the CTRL+SHIFT+DELETE shortcut to Clear Private Data by installing keyconfig
5. I had to specify the items i wanted to delete in about:config between :
   privacy.item.cache
privacy.item.cookies
privacy.item.downloads
privacy.item.formdata
privacy.item.history
privacy.item.offlineApps
privacy.item.passwords
privacy.item.sessions
privacy.item.siteprefs
privacy.cpd.cache
privacy.cpd.cookies
privacy.cpd.downloads
privacy.cpd.extensions-dta
privacy.cpd.formdata
privacy.cpd.history
privacy.cpd.offlineApps
privacy.cpd.passwords
privacy.cpd.sessions
privacy.cpd.siteSettings
privacy.clearOnShutdown.cache
privacy.clearOnShutdown.cookies
privacy.clearOnShutdown.downloads
privacy.clearOnShutdown.extensions-dta
privacy.clearOnShutdown.formdata
privacy.clearOnShutdown.history
privacy.clearOnShutdown.offlineApps
privacy.clearOnShutdown.passwords
privacy.clearOnShutdown.sessions
privacy.clearOnShutdown.siteSettings
privacy.sanitize.sanitizeOnShutdown
privacy.donottrackheader.enabled

PS : DOM Inspector was very usefull to know what to add in userChrome.css