OS X V10.5 Leopard :: Migration Assistant - Data/content Files Isn't Recognizing The Old, Original Contents?

I had an Imac running Snow Leopard... I mistakenly(?) thought i could change Permissions by selecting "Everyone" from the startup volume HD icon's Permissions panel and in turn, chose "Apply to All Enclosed Files and Folders" option thinking this would allow all other computers on a small office network to have total free and clear no-security-required, file-sharing read/write- access to this Imac's contents. After doing this and attempting reboot, I couldn't get access to the OS  at all even after i ran DiskWarrior and DiskUtilities, so, wound up doing Archive/Install - but used an OS 10.5 disk because i (mistakenly)thought that my 10.6 Snow Leopard disk was only an Updater.  So after installing 10.5 again I ran the OS 10.63 disk's installer, bringing the new System Folder up to Snow Leopard. I'm up and running - most system software updates downloaded/done.  Problem is now this --  stuff like:  Email Clients,  Itunes, Browsers, any Apps  that had associated data/content files isn't recognizing the old, original contents that belonged to them - instead, these apps all

Info:
iMac, Mac OS X (10.6.8)