I'm just throwing these questions out there, hoping for directions to tutorials or likewise - not really expecting any full answers (since both questions are about rather complex issues). Any help is much appriciated! Thank you! ;D
1. How do I create a transit network "hub" from a lot - like for instance turning train traffic into subway traffic at a specific place (BigDig style)?
2. Can I create a train replacement mod with more than one of each of freight an passanger trains (I want to simulate the illussion of regional AND interregional train traffic sharing the same tracks)? Note the "can I" in the question - I do think it's possible (after looking at Swampers latest train modd) but do I need extremly advanced modding skills for it?
1.) You need to add the proper transit switch properties that change rail passengers to subway passengers - and depending on the looks you might also need to creae path files that make the automata "disappearing" in the underground.
2.) Unfortunately, it's not possible to use two different passenger train skins at the same time. You can make two (or maybe even more) different car skins appearing at random, but you cannot make them showing up in a uniform pattern, i. e. one train (engine and cars) with a regional train livery and another with an intercity train livery.
Thanks!
And what are the "proper switch properties" for "train to subway" / "subway to train"? Can I use the SC4 Tool to make this or do I need to do it in the reader?
You should be able to do that in SC4Tool's TE Editor, but of course it can be done with the Reader as well. For a template, just look at the NDEX Rail to Subway transition.