A commuter train in Germany

Yes

Depends on the rail. If you are on a rail with a lot of turns, it actually makes a ton of sense because you don't have to slow down nearly as much; you can just swing into equilibrium.

so if you're on a train, traveling fast, and see a bend and curves ahead, you're thinking "i'm glad we're not slowing down, what could go wrong?"

Highway tooo the DANGER ZONE.

It is actually safer than every other vehicle with only one fatal accident which resulted in 5 deaths (per 1.5 billion passengers that were transported safely). The train derailed because contractors forgot to remove a safety measure from the rails after working on the construction. But still it is safer than going on foot... and It is fun to use!