There's usually bus 🚍 routes that stop at the train stations if you want to go that route.
I'd purchase online and then confirm everything when you pick up tickets at the station with a live person.

I took it once, although I can't answer any of those questions. id just say don't be on a tight schedule for your travel plans

Some trains allow bikes so you could ride your bike to a station. I believe you stay on the train the whole trip with stops along the way. Getting your own cabin is pretty sweet if you ask me.

Many times. Never had a sleeper just road over nights each trip, probably 8-10 hours. Spent most of my time I. The dining/smoking car (at the time) playing cards with others just hanging out.

Always booked online. No issues. Had a ride to the the train station so that wasn't an issue.

Made that trip 4-5 times a year. But that was between 2003 and 2005. Your mileage may vary.