Salzburg is 1.5 hours or so from Munich by rail each way. Depending on what you want to see/do, it can be done in a long day from Munich IMO. Again, depending on your interests.

With the time you have and given what you have said about your goals, I would pick either Budapest or Vienna and not both (Vienna is much more "imperial" IMO and I've been to both cities more than once).

Prague: rake away the trams and the cars in the old town and you'll think you are back in the Middle Ages which is probably one reason Prague has doubled for other cities in so many "period" movies.

Krakow I have not visited but I wouldn;t be surprised if it is, in some ways, similar to Prague.

Berlin. Get ready for a major major difference between those other cities and your endpoint. Well worth a visit even if you don't go to any museums at all.

Krakow is a tourist town, at least the historical center, and I do not know how much of "local" culture can be experienced in that part of town (I do not speak Polish). The Salt Mines are worth a visit. It is best to simply take a tour from Krakow. I do not know if that can be combined with Auschwitz, as they are in opposite directions.

I doubt that Salzburg is worth a day trip from Munich if you'd "rather spend time checking out unique neighborhoods, cafes and nightlife". A short visit is almost per force a tourist overview.

Some companies offer a full day tour combining both Auschwitz and the salt mine.

>>The Salt Mines are worth a visit. It is best to simply take a tour from Krakow.

Best? It may be efficient, time-wise, but doing it on your own is easy and less expensive.

You might enjoy taking the local public bus to the salt mine--you'll see the way real people really get around, not the inside of a tour bus. Once there, your visit to the salt mine will be with a group with a guide; you'll buy a ticket for a tour in the language you prefer. (I think, after we purchased tickets, we waited about 25 minutes for the English language tour to begin.)

We loved Krakow when we were there in 2003. Yes, the main square is touristy, but it is very pretty. We enjoyed Wawel Castle & Cathedral (good way to learn some Polish history) & enjoyed exploring the neighborhood between the Main Square & Wawel. Found some great restaurants that way. St. Mary's church is worth a visit (a beautiful small church). We took a local bus to the salt mines, definitely worth a visit. very unique. Went with a guide to Auschwitz, needless to say, very depressing. I'm of Polish descent so I grew up eating Polish food, so I loved eating in Krakow. It's a very pretty city, you should definitely go. Very different from Berlin. I would suggest 3 nights in Krakow, at least, & recommend Hotel Saski. For Prague I recommend at least 4 nights. We LOVE Prague & have been there twice. Make sure you go to Vysehrad, up on a hill overlooking the Vlatava River. Lovely small church (St. Peter & Paul)& the beautiful national cemetery, & ruins of an old fortress. The best part is: Vysehrad is much less crowded than the rest of Prague. We were in Prague & Krakow in October which is a nice time to go. Fewer tourists. In Prague, restaurants/pubs sold hot mulled wine from their windows. Nice treat when it's chilly out.

St. Mary's church is worth a visit (a beautiful small church).

If St. Mary's is small, what's big?