Well, without the cutscenes, the Injustice 2 story might last you approximately 12 hours, give or take. This assumes you're playing at a decent pace and not getting stuck on difficult sections for too long.
They often interact as teacher and student. Luna, with her vast knowledge of the old magic, can teach Twilight things that are not found in modern magic books. For example, Luna might show Twilight how to communicate with the spirits of the night.
Well, the story behind the 'Twilight Music' in 'Twilight Princess' could be tied to the game's plot and the world of twilight. Maybe it plays a role in revealing secrets or triggering certain events.
Sure, the Destiny 2 beta allowed for skipping cutscenes in the story. It's a common feature in many games these days to give players more control over their experience. If you're not into the story part and just want to get to the gameplay, it's there for you to use.
The cutscenes are very important. They help to tell the story. Without them, we would not understand the context of the medical cases or the relationships between the characters as well.
In general, the Twilight Princess manga is regarded as canon. It adheres closely to the key elements and plotlines set in the original franchise. Minor deviations might exist for artistic or narrative purposes, but the core remains consistent.