Opening .BIF files, other issues...
I was able to open the .bif files in NWN Explorer. DragonUnpacker does a poor job, in comparison. You can view the file names and proper extentions with NWN Explorer - not .raw, but .mdl, .txi, etc. as well as their binary format. However, you cannot view the model directly or view the ASCII.
Certain features of these files give the impression that they are purposefully distorted. I hope this is not the case.
Unfortunately, I really don't have the skills to do much with this. Hopefully someone else out there does as I have the resources to 'make it happen.' (Read: -Hint-hint- Drop me a line if you're interested.)
For purposes other than modding, (if you just want to look around) the pre-rendered movies can of course be opened with RAD Video Tools/Bink. Sound files work in WinAmp and RealOne, but not WindowsMP, provided you change their extensions to .mp3. Dialog (dialog.tlk) can be viewed with NWN Viewer. It is organised by Resource Name. The NWN tools mentioned above can be obtained at NWVault.com.
I'd like to see this game modded, but their is a substantial amount of work involved in the creation of a workable toolset. I'd be hard at work on this already myself, but my background isn't even in a relevant ballpark. All that I can do myself is explore which tools are out there for viewing and editing (and try to find people with some serious skills and free time).
The Odyssey engine is substantially based on Aurora, so while any modding attemps would be nearly from scratch, there is this advantage.