I've done a bit of touring and what you are suggesting is not possible as an enjoyable holiday. 200-250 miles per day is MORE than enough. And even at that, you'll want a day off the bike. Making big mile plans is all good and well, until something happens. Example, last year I was going from Nurburg (we'll come to that in a minute) to Bagni Di Lucca in Tuscany. 1400kms. I got to about 600kms and the exhaust collapsed. This took 4hours and 325euro to repair as I was in the middle of nowhere. I'm not saying this will happen to you, but it might. Another time my friend and I took five days to ride to Tuscany via Holland, Belgium, Germany (lake konstance), Austria and the Stelvio Pass before arriving at our destination. It rained very very heavily until we reached Italy. It was miserable. You really have to consider such things.
As an additional point, and not to be a smart arse, if you want to go to the Nuremberg ring (where they tested VW Beetles and shit), that's fine. But it's probably the Nurburgring Nordschleife your talking about, and around 400km separates the two. I've done many laps at the Nurburgring in the car and on the bike over various trips. It's worth remembering that the Nurburgring is a road, not a track. There are laws in place and you should follow them. It's also important to note that you are liable for any accident you cause, which can become very expensive very quickly. Especially if you hit someones supercar. I wouldn't buy tickets for this prior to showing up because it could be raining and you'd have to be an idiot to take your bike out in the rain, or someone might crash just as you arrive and it could be closed for the rest of the day. I've been there before and it was a long wait to find out I'd wasted my money. It was worse for the three bikers and one driver that had just been killed I suppose though.
An 8 day trip I think no more than 1200 miles max. Unless you enjoy endurance riding and grinding out a challenge. But if its a leisure trip, relax and enjoy it.
http://www.nuerburgring.de/en/drives-fun/drives/touristenfahrten/tourist-rides-nordschleife/opening-times-nordschleife.html