I'm not going to quibble with AnTyx' itinerary, which give you plenty to see and a plausible route. Of course, for each suggestion there are certainly a dozen equally valid counter-suggestions. And no matter how you work it you'll surely miss lots--it's the nature of things that in the process of getting somewhere you become aware that you're missing far more than you're seeing. Journeys are therefore exercises in deciding what to miss out on as much as what to see.

But what's really lacking here is consideration of the seasons. Your six month trip is going to include parts of three seasons and maybe 35 degrees of latitude. I've been up to Nordkap in mid-September, and things were definitely getting marginal for motorcycle travel. November/December in central Europe can be brutal, not to mention dangerous. Autumn rains quickly get old in a lot of places, and early mountain snow will definitely interfere with the best laid plans. On the other hand, summertime heat can strip you of the will to live--or is that just me?

I'll add only that when I find myself predicting daily mileages, I somehow forget to allow for bad weather. Yeah, I can put in my allotted 300 miles through blustery November rain, wind and snow and the short days of late autumn....but it's sometimes remarkably unpleasant as well as marginally safe.

YMMV, and I hope that's helpful.

Mark