Dachau, Salzburg and Bamberg train questions

Thats the right station for Bamberg. There is only one.

For Dachau do I buy the Munich XXL?

Correct.

For Salzburg the Bayern ticket?

Correct, provided you depart after 9am on workdays (no restriction on weekends).

Here is a zone map of the Munich-MVV transit district. The Munich XXL ticket includes travel within the two inner zones, white and green on the map. Assuming you are staying in the downtown area, in the white zone, the Munich XXL Tageskarte would be the ticket for travel to and from Dachau by S-Bahn and bus.

On the Bahn website, inputting "Bamberg" will get you a selection of destinations. "Bamberg" alone or any destination with Bahnhof in it, like "Bahnhof/Post Bamberg", will be the same destination, "Bamberg", in the final details. However, there will be other destinations, like "Bamberg, Promenade", that are a ways from the Bahnhof and will require an additional bus leg to get there. If in doubt, use the map link, under details, on the website.

If you are using an advance purchase, Savings Fare ticket, understand that travel on any leg with a long distance train, ICE/IC/EC, will be restricted to that specific train, so when specifying the stopover time, make sure it is a time you can live with. You can also go to "means of transport" and uncheck all long distance trains for the second leg, Bamberg to Berlin, but, in this case, the would not be practical.

Correct, provided you depart after 9am on workday

Actually, you can depart earlier, as long as you purchase a separate ticket to the first station you stop at after 9 AM. For instance, you could leave from the Munich Hbf on the 8:55 Meridian train as long as you also have a 1 zone MVV ticket to travel from the Hbf to Ost, which the train leaves at 9:04.

Thank you. I think I'm understanding better. If I were to do Dachau & Nymphenburg on the same day (and I'm not sure I am) would the same ticket get me to both?

dbordsave, at the risk of stating the obvious (but nobody has specifically said it so far):
Bahnhof = station, usually means railway station, unless they add something, like "Busbahnhof" (= bus station).
Hauptbahnhof = Main station, usually abbreviated to "Hbf". Example "München Hbf" is the humongous one at one end of the city centre where all the long distance trains start and end. All other ones, München-xxxx etc. are local stations.

If I were to do Dachau & Nymphenburg on the same day (and I'm not sure I am) would the same ticket get me to both?

Yes of course. The Munich XXL covers the innermost and the green zone on the second map shown on this page ("wo endet München XXL?"). Nymphenburg is inside the innermost zone.

If you go out to Schloß Nymphenburg on a day other than you trip to Dachau, you won't need a München XXL ticket, just an Inner Zone ticket. The best way to get to Nymphenburg is to take the #17 tram from the Hbf.

Bahnhof = station, usually means railway station, unless they add
something, like "Busbahnhof" (= bus station).

In Germany, at least, bus bahnhöfe are commonly designation as ZOB, Zentrale Omnibus Bahnhof.

Thank you everyone! I'll be there in 3 weeks & I'm very excited!