hmm.
You have validated the contents of Netinfo, right? Or are you using LDAP or whatever else for user authentication? Do this BEFORE fsck.
Filesystems are made of several things. Metadata (data about files) , data in the file, and some part or all of a device like a disk. The metadata maps the data onto the physical device. Metadata also involves permissions, ACLs, inodes and other stuff like blocksizes.
When a filesystem goes South it usually means the metadata got messed up, or there was a physical problem with the disk. What I am seeing is 'interesting' metadata.
I am assuming you ran low-level checks on disk physical integrity, right?
You appear to have metadata issues, a lot of them. fsck will try to fix it. You will probably see complaints about some directories you never heard of. If you have files in those wierd directories, you have to see if either fsck can move them or you may need to try to recover those files.
Do not go messing about with xattr to fix the @ metadata until after fsck pronounces things okay. @=extended attributes, kind of cutsie information about files. After fsck have a go with xattr. I think there is no help for xattr, so try xattr -h or xattr -? to get some idea how to use it.
I'm guessing the ACL's are pure nonsense. Try:
The ACL Permissions pane
to play around with the ACL pane. If you see numbers instead of text for user ids or groups in an ACL it has to be a garbage ACL. Or something from a previous app that no longer exists - meaning it is: dangerous, a problem, or pointless. I think the ACL pane complains on certain problems. Do this post-fsck.