Am I being too ambicious with all my stops?

Take the train to Nuremberg. Get a car there if you want and return it in Munich. You can also visit Bamberg, etc by train. Those 3 plus N’berg are too much for only 2 nights.

Yes, it is too much. First, you should not drive after a flight here, this is as dangerous as driving drunk. Spend your first night in Munich. You are trying to see 7 cities plus extra sites in 6 days. How much will you see? All of your time is spent traveling.

Have you plotted the travel time between all these places? Taken into account traffic, pitstops, eating, gas stops, parking searches? How about the time standing in line at the castles? Yes, you are ". . . trying to cram in too much in my 6/7 days. . . ."

I wouldn't attempt to do half this much in the given time, and I lived in the area for 3 years. Please heed the advice of getting a good guidebook ( Rick's or someone elses) and read up on the towns in Bavaria to decide what your priorities are in the time available.

Please don't drive right after getting off an overseas flight, You will be jetlagged, and that doesn't mix well with autobahns. Take the train. AND speaking of autobahns, make sure you account for travel times when making your plans. Just getting from Nuremberg to Fussen would eat up a whole morning, for example . Use the via Michelin website and/or Google maps to plan your routes but add an extra 25% to their time estimates.

So, this is a 6 day trip.

Here's how to think about a trip. For each day on a trip, you have a morning, afternoon, and evening period. In those, you can do one activity. That means that for your 6 day trip, you have 18 slots. In your itinerary, you have 12 cities (I think). That means that you have 12 trips, and that leaves 6 slots to actually do some sightseeing.

You are probably spending $2000 for this trip. Sounds like a bad deal.

Here's a better idea.

0-3: Munich
4-5: Nuremberg
6: Munich and home

Do it all on train. A car is not needed for a short trip such as you are on.

Im actually flying in from Paris after being there 2 days for work...But I get what you're saying.

Im wondering if I should eliminate the whole northern region altogether. That was an afterthought as my main focus was always the Bavarian region. But it's so beautiful up there I felt like I just HAD to include it (first world problems)

Also in this thread: take care of spellings of destinations. "Rothenberg" is the wrong town, it is Rothenburg odT. Otherwise you will be really guided to the wrong town.

In general for you: Less is more. In one region the next half-timbered house will not look differently to the last one, maybe in southern Bavaria.

staying in Nuremberg (2 nights), want to visit Wurzberg, Bamberg and
Rothenberg odt.. If I had to eliminate one, or two, which?

Absolutely over-ambitious, even if you run through these towns. Concentrate on two where you like special things to do, e.g. Nuremberg castle or whatever.

driving to Fussen (2 nights). want to visit Newstn Castle (not sure if
I am visiting the inside), Marienbrucke, Gondolas to Zug, Garmish,
Mittenwald, Eibsee, Linderhoff palace, Partnache gorge

Same issue, same solution approach like before. It seems that you do not have enough time to write the names of places right you want to visit.

Any advice on the best roads to take when traveling from city to city?

Whatever road you might take. Calm down and drive carefully. Here WeGo is a good trip planning and navigation tool in Germany. It is the material built-in by most car manufacturers.

Take care you have a valid driving permission, not license only. Take care of tyre requirements, of traffic rules and traffic signs.

Any tips on how to tackle this? Is it too much? All advice welcomed!!

Again: less is more. Take yourself time for a place. Taking snaps take seconds and does not create memories, taking only 1 good photo minimum takes minutes and creates a little memory, experiencing moments of a place by enjoying the beauty of it or putting it in mind into a historical context create memories which really last a lifetime. If you invest money into a travel, you need to invest time at destinations - otherwise the money was wasted.

Im wondering if I should eliminate the whole northern region altogether.

Probably a sensible choice. Germany is very pretty all over, and there are many places to go and see. Remember that when you don't see one thing, you see another thing. The key is to spend the time doing something fun, and moving from location to location is usually less fun. As Markk notes, you are probably spending some money for this trip. Slow down, enjoy the locations, don't get caught up in the "see it all" thing. You can't see it all. See some things more slowly and with more depth.

Vacations are supposed to be fun. Running around like a crazy chicken is not fun.

Thank you everyone! I am reconfiguring things a bit based on your advice. It has been very helpful!
Since my biggest interest is southern Bavaria, I'm going to stay 3 days in Fussen and 3 days in Munch, maybe take a day trip to Nuremberg if time allows. Again, thanks!!

viviand954, I'd consider staying in Garmisch instead of Füssen. The castles still accessible from there, but I think its closer to more things to see and do.