You can skip the tutorial and the introductions easily. For tutorial it literally asks if you want to skip it and for the introductions you can just choose the second option when you first step outside of the train. (It's usually something like "Sorry, I need to be on my way" or along the lines. Depends on the character)
You do not miss anything by skipping the introductions and if you skip the tutorial(intro) you only miss the chance to get the Janitor's weapon.
I'll look into the "field save" mechanic. Not a bad idea at all.