re: Honeymoon Question-- Europe

+1 on the side trip to Salzburg...it's an easy train ride if you don't want to rent a car. Town is small, charming, and easy to like. A few decent markets, loads of culture, and some quirky things like:
--Stiftsbackerei St. Peter: a water-powered flour mill dating from the 12th century...it was refurbished & the power is used to grind grain. A small bakery sells breads made from the flour ground on site. Link: A short walk away is an interesting cemetery.
--Salzburger Schranne, a food market well worth a visit, esp if you are renting an apartment: https://www.salzburgerschranne.at/

If you do rent a car, you can stay at a traditional guesthouse or farmhouse a short ride out into the countryside...the scenery is lovely, English is spoken widely, and the beer is fantastic. Salzburg has a great tourism website with lots of accomodations photos: LINK
These farmhouse/guesthouses are usually simple in style, but often with great views/scenery and run by families. Some will do half-pension (1 meal a day, either breakfast or dinner), which can be a good value.