Sean, you have two different sets of honeymoon plans (Germany post). The region of Switzerland you plan on visiting is well worth it. If you go with Switzerland and like hiking in general, skip the Black Forest- I like it but more is to be had in the Bernese Oberland and the Bavarian Alps. Especially do not base in Triberg.
Skip staying in Nuremberg, do as a long day trip from Munich (hour by train). Stick with three bases, preferably two, just a personal preference. Once back in Munich, drop the car. Munich is worth three days for me and there are a few attractive places close by which can be reached by public transport - check out Murnau, Bad Tolz, Chiemsee, Regensberg, Dachau, Ulm, Augsburg and more.
To name a few, close to Fussen are Kempten/Ottobeuren Abbey one way, Oberammergau/Linderhof/Ettal Abbey the other. Spend a full day hiking to the King's House on Schachen, or the two gorges in Garmisch-Partenkirchen. Hike around Hopfensee, bike around Forggensee. See the castles, hike way above the castles and around Alpsee. When I'm in Hohenschwangau, I always make a point of dining at the Hotel Müller. A little further, Mittenwald and the Leutasch Gorge.
Grindelwald (good suggestion to stop off at Lindau on the way, a charming spot). My experience with that part of the world is one week in Bern as a youth, with a few side trips into the countryside, and three or four nights around Spiez on my honeymoon. It's the most dramatic part of the world I've seen, in terms of mountain scenery. If you get tired of the mountains (ha), Bern itself is a pretty city, and I remember finding Fribourg attractive. As a youth from Ontario, Interlaken was a gem for me, though some on this board might say otherwise. I also had to do Reichenbach Falls, with a photo of my new wife pushing me over the edge. Oh, and a cruise on the lake, depending on the time of the year.
Someone in your Germany post suggested that Munich is not romantic. Skegness and Lloret de Mar can be romantic in the right company, Florence and Paris cannot be in the wrong company.