I'm considering using Salzburg as a basecamp for a 7-10 day visit to Europe next summer. I'd greatly appreciate any suggestions for day trips using either train or car. My girlfriend and I are also wanting to visit Prague and friends in Fulda, Germany which is not too far from Frankfurt. Would it be feasible to fly into Munich and then fly out of Frankfurt?
We did the opposite, flew into Frankfurt and out of Munich a few years ago. Made sense for our trip and wasn't more expensive than R/T from either. Maybe we were lucky? If it fits your plans, look into it.
I can see basing in or near Salzburg for 7 days. We prefer the Berchtesgaden area as a base, have stayed 18 nights over 5 trips/stays in the area, but we use a rental car. Basing outside Salzburg in St. Gilgen could be a good option without a car.
Places to visit could include:
Salzburg, the Wolfgangsee (St. Gilgen, St. Wolfgang, Strobl), Hallstatt, Werfen Ice Caves and Hohenwerfen Fortress, Salt Mine in Hallein, Berchtesgaden including Berchtesgaden, Salt Mine, Eagles Nest, Konigsee, Jennerbahn, the Rossfeld Panorama Road (with a car), Bad Reichenhall, and more.
Hope this helps.
If you are going to base yourselves in Salzburg and see places around Salzburg, I would fly in and out of Munich.
I just reread you OP and I see you will be in Fulda, so flying out of Frankfurt makes more sense. I've done that before (2x) as into Frankfurt and out of Munich. Book your flight as an "open jaws" or "multi-city" ticket.
I am not sure I would agree with flying in and out of MUC while using Salzburg as a base. We are going later in the month and found that fares from ORD to SZG were cheaper than to MUC. It may be a temporary thing due to Oktoberfest (going there too) but it pays to compare. The awesome thing about Flughafen MUC is that they have a brewery right at the airport, which can start the trip off on the right tone if you don't have to drive. There's more direct flights to MUC, but then you will have to take a train to Salzburg anyway so it's the same difference.
Up to five people in a party can take the S-Bahn from MUC to Muenchen Ost where they get the hourly Regional Express to Salzburg with a Bayern-Ticket. It cost 23€ for the first person, 5€ more for the next four riders. Time from MUC to Salzburg Hbf is 2h17m.