I'll have a look at doing up a quick video tutorial for an interlocking tower for a diamond crossing. It's exceedingly simple in reality, but it might help explain it better than I am on the forums.
Changes to Procedural Track are unlikely to cause changes to the signalling; that is a separate function. With the current system (ie splines, rather than 'component' track, or similar), two crossing tracks (not diverging tracks) do not interact in any way, and as such the signalling won't detect it. And since there *are* times where you don't want that interaction (driveable cars, aircraft, etc), you would still need the ability to actually configure when you want this to occur. Hence the introduction of interlocking towers, which allow you to setup actual paths, exactly as the real railway systems do (it is based upon the NX system, ie 'eNtrance - eXit'; you set an entrance and an exit and then Trainz gives you the route and signals if it is available, otherwise you wait till the path is clear and then you get the route and signals!).
Regards