I think turning loops are something as train fuelling with water towers and maintenance depots – really not needed, but adds some immersion. It is my personal wiew, I am not trying to force it to anybody.
And likewise, I’m not forcing my view on anyone. In OpenTTD, there is an option to choose whether to allow the train to self-reverse at platforms. I personally choose to have this enabled, but I still think those who want to have it disabled should have the option to do so. Of course, if TF enabled de-coupling, shunting etc, I’d be more inclined to play with self-reversible trains disabled. As well as turning loops (balloon loops) and depots (which would be more realistic if the depot was as long as the longest train it could handle), the trains could make use of triangular junctions (wyes) and escape tracks (Headshunts), turntables and even marshalling yards (classification yards).
#7: If this is added, it should be optional. Sometimes, we may later want to add a switch, and if the switch straddles a segment-boundary, this would make it impossible to add. Perhaps we could just have the ability to divide a large segment into X smaller segments (but there should still be a mimimum segment length in this case).
Actually, if segment-joining/merging was implemented, this would no longer be such a problem.