Eric: yes there is a higher account level than "admin"...root

you can temporarily become the "root" user....OS X automically makes the root's password the same password that YOU chose when installing OS X the first time...

at the command prompt, just before attempting for the nth time the limewire install....type "su root". you'll be prompted for a password....you will now have temporary root access...until you close the terminal window in which you used "su root"

i have no idea if that will help but it's worth a try...

btw, are you sure OS X isn't case sensitive?? have you tried with the proper capitals?? just wondering because your error message seems to indicate that OS X isn't recognizing the file or directory ("no such file or directory"). maybe since it's looking for the proper capitals in the proper spots....come to think of it....even if OS X isn't case sensitive....maybe the installer program is...since it seems to be a Unix port....ahhh the beauty of OS X's unix kernel.....a LOT of software will be easily recompiled to run on our superior (at least to Windoze) OS!!!!

Good Luck and Cheers!
Luc