regarding 1):

if you lay your tracks properly, plan your lines thoughtfully and place signals in the correct locations, then your trains will not become stuck unless you run much more trains than your network can handle. basically you do not need any complicated rules for your trains to follow as long as you build your network properly. from the beta videos it appears that most people are already overwhelmed with the placement of simple signals, so i think there is no need to complicate things further.

what exactly do you mean by building complex routes/lines?