Apps Quit Unexpectedly constantly "Crashing"

[lawill5]

Greetings Mac Family, I have an iMac 20in G5 PPC w/ 2GBRAM/250HD 10.4.6
Recent events: Burning Purchased ripped DVD's and deleting the TS_Video folders afterwards using Secure Empty Trash; Installed Tiger Cache Cleaner, macromedia flash 8;
Incident: Mon-night was downloading using Limewire some homegrown vid clips (.asf and .avi)
attempted to open files and started getting the crash window "The application "QT" quit unexpectedly after it was opened MacOSX and other apps aren't affected Click try again to temporarily restore to default settings, or retry to open or report to send details to apple.

Apps affected: Quick Time 7, Itunes (my music directory is now missing some serious gigs of music, lets say 20GB to be easy; since my ipod was connected, it zapped the ipod as well except for podcast and music videos), DivX 6.5 for macs, Real Player, Tiger Cache Cleaner and even safari/firefox when I attempted to go to apple.com to download new Itunes/Quicktime but I think a lot of this revolves around QT b/c when my work laptop goes to the same website yesterday apple was running the mac vs pc commercial using QT plugin.. I initially thought some Wack job Windows guy was getting back at macs and I was one of the first hit, but now I almost think its a tiger cache cleaner and deleting some important directories/libraries even and I don't know how to fix it.
I have run disk utility and it repaired some permissions on the harddrive, restarted, turned off and on, used my baby mama's account to no avail. Also, I'm even having issues connecting my usb jump drive of 1GB which I downloaed QT/Itunes to from work laptop IBM-T43 its not recognizing it and the jump drive lights up green as if power is getting to it.
Where are the actual run files kept that the icons in Finders' applications folder run from? could I have deleted some important libraries??

I'm open to someone contacting me personally if need and walking me through some things.

Family, I'd appreciate if yall would look out for me and help me out here, I feel naked with out my Mac man!!!

[lawill5]

I was able to get my Jump drive to work correctly after turning off my machine and then rebooting in the morning. So now jump drive works.
DVD player and Toast Itanium 7 still work b/c I was able to burn a dvd of my music videos that are in mpg format to save them from getting wiped out.

I used App Zapper to kill and get rid of the following applications, Tiger Cache Cleaner, QuickTime & iTunes, then it rebooted. I re-installed QT and iTunes via the .dmg files I had loaded onto the jump drive from work laptop, However I didn't secure empty the trash until after I attempted to restart QT only to have it crash when opening again. So of course I secure emptied the trash and restarted the machine. Itunes and QT still crash

Any ideas as to why??? Oh, Windows Media Player 9 is immune to all of this but Real Players can't seem to play either without crashing.