First off I should say that I'm not very good at this sort of stuff but I thought I'd just try and help anyway, so...
I've been looking at exactly what the installer is doing to find out where it's going wrong and I've noticed a few of things:
1. The first patch it tries to apply (to the AppleTV.framework) is supposed to just change disk0s4disk0s4 to disk0s4disk0s4 but it just pastes the code in the right hand column and it also cuts off the laste half of it
2. Then I had a look at the "gdb" part and the "text.out" etc but at the moment I have no clue what is going on there so I can't help with that at the moment but I'm pretty sure something is wrong because the decrypted file is virtually blank!
3. A similar thing to my first point also happens again though - when patching the "Front Row" binary it basically halves the file again!
4. Finally on a different note.. when the installer first gets the frameworks from the "osboot" it doesn't copy the aliases properly - it copies the original file and puts it in the aliases place, so because the installer it only patching the single file it's leaving unpatched files in the frameworks directory so if "Front Row.app" tries to get to the file (through what should be an alias) it will get the original, unpatched binary - if you compare the binaries on the osboot to the ones the installer moved you should understand.
I hope this helps you - if it has and you need anymore help, or you need me to explain anything I've said here, feel free to email me.
Thanks for all the work you've done so far anyway. I can't wait for the installer to be up and running!
Seb.