What do they mean?
I've turned to the dictionary but still can't figure out what they mean:
1) This area is still off limits to Louvre security.
2)(His awkward face had been shattered by a fist in Spain...)The physical flaw barely registered now.
'off limits' means that they are not allowed to enter. It is a little strange that the security people aren't allowed in, as they normally keep people out, but that is what it says.
Flaw = defect
If something 'barely registers', it means that it is not really noticeable.