... I only have 7 days of riding. and I usually spend 12-14 hours riding each day (sunrise until near sunset).
No problem only having 7 days for your European trip. But, I think you will need to re-evaluate your plan to spend 12 or 14 hours each day riding if you want to focus on riding twisty mountain passes. There's a huge difference between doing long rides in North America ("covering miles") vs. doing challenging rides in the Alps where you are dragging pegs and navigating 180° switchbacks every 90 seconds in mountain passes. Besides, if you spend all your time riding the motorcycle, you won't be giving yourself the opportunity to enjoy the scenery, the cultural differences, the historical sites, the food, etc.
I do two 3 week long riding trips in Europe every year, using Zurich Switzerland as my base of operations. I used to live in Zurich, so I know the area pretty well.
Given that you have 7 days, that means no longer than "3 days outbound, 3 days inbound" from your starting point. You can completely write off your first day due to jet lag, even if you fly business class and sleep all the way through the flight on a lie-flat bed. It's just not safe (and no fun either) to try and go riding after spending 8 hours at an 8,000 foot cabin altitude, and then getting off the plane and confronting a 7 hour time zone difference. In other words, the plane may land at 9:00 AM German time, but your body clock is still stuck at 2:00 AM Texas time.
So, what all this means is that you should pick a small area - no more than perhaps 200 miles (320 km) straight-line distance away from whatever location you land in - and focus on exploring and enjoying all the routes available in that area. Believe me, anywhere in southern Germany, in the Swiss Alps, or in Northeastern Italy will have far more interesting roads to explore within a 200 mile radius than you could possibly ride in
six weeks, let alone one week. Americans tend to think that roads like Deal's Gap are rare and unique - in the areas mentioned in the last sentence, you will find half a dozen 'Tail of the Dragon' roads within a 45 minute ride from wherever you slept last night.
My suggestion to you is that because this will be your first trip to Europe, you focus on riding in the Swiss Alps. The scenery is far more impressive than in southern Germany, the mountain passes are the best you will find in Europe, and just about everyone you will encounter who is riding a moto, working in a hotel or restaurant, or otherwise engaged in serving the public will speak English. That's a big benefit to you if you are not fluent in German, French, or Italian.
Switzerland is a bit more expensive than Germany or Northern Italy, but not terribly so. The quality of restaurants & hotels is first-class, you won't find any unpleasant surprises. The roads are as smooth as billiard tables, they are the best in Europe. You will not find any yahoo drivers or loud exhausts in Switzerland, that isn't tolerated. But, on the other hand, the Swiss police are pretty sensible about motorcycling as a sport - provided that you
strictly respect the speed limits in the villages, they won't bother you for speed out in the uninhabited mountain passes.
Get yourself a paper Michelin Map of Switzerland (it's Michelin Map number 729, you can get ne from Amazon if you can't find it at a large bookstore) and do some internet research on motorcycling in Swiss passes. You can sketch out a number of circle tours such that you can spend perhaps 2 days in each hotel, heading out in the morning and riding perhaps 2 or 3 passes each day before coming back in the late afternoon. You don't want to be changing hotels every night - that takes a lot of time and really detracts from the enjoyment of a trip.
I hope these suggestions help you with your planning. FYI, I'm heading over to Zurich at the end of the month for 3 weeks of riding.
Michael