On one hand, from the passengers' point of view, it will be a terminal station -- meaning that all passengers of the arriving train will get off, and all passengers on the departing train will board there. You can't use the 6 minute turns in Frankfurt as example for that -- 10-15 minutes in Vienna Westbahnhof is more like it.

Then, you'd have to service trains in LA after a full turn (that would be up to 7 hours 20 minutes without servicing, with runs in 213-minute train pattern #3 both ways), or devise an operation plan in which runs from LA to SF are always followed by a run from SF to Merced, where there would be time for servicing.

All in all, I have a very bad feeling about this TBT project. The seeds of several future problems will be planted, even with the improvements you sketch in the second and third diaries.

_{*Lunatic*, n.
One whose delusions are out of fashion.}