I would expect the ice caves at Werfen to be a big hit with teen guys. On arrival at the Werfen train station, you can take the scheduled public bus service from the train (a few times a day) or walk a short distance to a private shuttle that runs more frequently. The shuttle historically has been cash only. I used the shuttle service, and I thought it was very good.
Königssee is great. If you haven't seen the recommendation here, a great day can be had at Königssee by catching the boat all the way across the lake to the Salet stop. Walk around 15 minutes to Obersee (a small, gorgeous lake in and of itself). Then hike along the right side of the lake to its opposite side, ascend to a very nice alpine meadow surrounded on three sides by granite peaks, and then hike on to Röthbach Waterfall. It's an easy high hike with a big pay off. The part that consists of ascending and hiking on to the waterfall is accompanied by cows who are grazing in the mountains for the summer. There is a snack hut at the opposite side of the lake that includes fresh milk among other things.
I have not been to Wolfgangsee, so I can't comment on it.
The marionette shows are great.
One SOM site not included in tours is the Felsenreitschule -- the location of the von Trapp family's final performance in Salzburg in the movie. The venue is now enclosed with a retractable roof and is one of the venues for the Salzburger Festspiele. The way to see it is a tour of the Festspielhaus (Festival performance house). It's a 50-minute tour that gives a bit of history on the festival but also on the city's history. I thought it was excellent. https://www.salzburgerfestspiele.at/en/guided-tours
