the TG NewDark options menu is a clone of the T2 version, the new options work, but the effects need to be implemented into the missions first.
no idea what are you trying to accomplish, but even though the legacy engine is included in TFix (and it works - well, sort of), you really shouldn't be using it unless there is absolutely no other way around (or if you want to do something extremely specific) - currently, running TG under NewDark is superior to running under oldDark in every imaginable way.
also, the oldDark note still applies - feel free to mess around, but don't complain if things go south real quick.
Basically I want to run the original game, just with the technical
fixes so that it works on modern systems. For example, runs in Windows 7 and supports widescreen resolutions. Not interested in any enhancements, artwork or data updates, post-Looking Glass bug fixes, Thief 2 features, increased colour depth, etc...
So if the oldDark delivers everything the original game did when it came out, but can work in widescreen. I'm happy.
Hope I'm being clear. If my approach will not achieve my goal, please let me know.