Advice on travel and accomodations in Germany

Trying to make plans for a trip to Germany this year, and never having been there we have a lot of questions about how to get places. We'll be making this trip in October. Our general itinerary is: * Arrive in Frankfurt * Travel to the Loreley valley area of the Rhine valley. * Spend about 4 days in this area seeing the local sites. On one day, we'll make a visit to Trier and Konz. Also want to take a boat tour on the Rhine of some sort. * Travel to Essen for the Spiel Essen. Have about a day and a half to explore there, including possibly taking a trip to Koln. Then spend 4 days at Spiel Essen. * Take a long train ride south to Bavaria, where we will have another 5 days to sight-see. We particularly want to visit Berchtesgadener Land and Neuschwanstein castle.
* Travel to Munchen for the flight home. We'd really appreciate advice on how to handle this travel. For the amount of train riding we'll be doing, will it be better to get a Eurail pass, or just by tickets on a trip by trip basis? Any ideas on how its best to get to any of these locations? Is the train best or are there better bus trips? We'd prefer scenic methods of transportation. Any thoughts on whether it would be better to stay in a central place in Bavaria, or stay near each location? (We'd also love to go to Bayerischerwald, but it seems like its too far away). And one other train question - there's a big jump in prices for the Eurail pass for more than 10 days of use. Is there any reason you can't buy two passes for lower amounts of time? This would actually be cheaper than one long pass. (Cross posted to the transportation forum)