Need guidance on train ticket options in Germany

I assume you mean Rothenburg. There is a least one town called "Rottenburg" in Germany.

Use the German Rail schedule webpage to find information about times and fares.

Looks like the fastest way to get to Würzburg from Bad Cannstatt is to take the S-Bahn to Stuttgart Hbf and then a direct RE to Würzburg. All this travel can be done with a Baden-Württemberg (Länder)-Ticket, 23€ for one person, 5€ more for each of up to 4 additional persons. The Baden-Württemberg-Ticket is an all day (after 9 AM workdays) pass for unlimited regional train travel in Baden-Württemberg and to some border stations (like Würzburg) outside B-W. It is also valid for all conveyances in the Stuttgart Verkehrsverbund (metro district).

A full fare ticket from Würzburg to Rothenburg is only 13,30€ per adult. Unless you have a large group (more than two adults), that's the best fare. Buy the ticket from the counter in Würzburg or from an automat.

You can go from Rothenburg to Salzburg an hour faster with a ticket that includes an express train (ICE, IC, or EC), but it will cost more. If you use regional trains only (change means of transport on the Bahn webpage to local), you can use the Länder ticket for Bavaria, the Bayern-Ticket. Same price and conditions as the B-W-Ticket. I did a similar trip (to Berchtesgaden) years ago. You'll change trains in Munich. You can stop over for an hour and have lunch at the food court in the Hauptbahnhof and take the next train. Regional trains to Salzburg run hourly.

Regional trains do not have reserved seats. Normally there are enough seats on a regional train that reservations would not have been necessary if they had been available, and there is no advantage to advance purchase. A Länder ticket can be purchased on the morning of travel for the same price.

Lee, I was hoping that you were still out there since I had read a similar post by another newbie to the German train system. Thanks again for your input.