I have the sources myself on my computer and updated the missing entries.
But I had a problem on the update process for Dutch so I didn't post them on the svn yet, so of course they don't contain xFede changes (nor french, japanese, german or dutch either)
About your request : I prefer that xFede post them as italian.lang (not zipped)
It's easier for me, I just replace them in my language folder without the need to extract them one by one.
And I don't see where it could become not safe if it's not into an archive. download the file, and save it. It stay in UTF-8 without BOM unless your internet browser is bad and show the file instead of downloading it (but when posted on Mediafire it's never displayed, only downloaded).
All other translators post the .lang as text file.
Another thing I don't understand :
"mark it as revised (not fuzzy)"
How do you mark a translation as revised?
If you don't need to translate a string, just let it empty and it will use the english version.
It's "supposed" to be 100% translated, so if a string is empty it's on purpose, you only need to translate new added strings with newer revisions.
You can't add comments in the file, it will be deleted when I updated them.
At least, it's how I work when I update the french.lang file.
Edit:
If there's strings that a translator don't understand or need help from someone else to translate it, just ask in the post when you link to the file, so other translator/team member can update what's missing.