Hello All ,
Coming this September I have some 4 weeks of time off to spend on a tour across Europe. Weather permitting, the mountains of Czechia and Slovakia along the German and Polish border are looking like an alluring proposition.

Judging by the view on Google Earth Germany will be best crossed as quickly as possible and I'm set on avoiding the autobahn and taking the country roads. Entering around Rheine (north of Munster near the Dutch border) and with sights set on Hof (German Czech border) there's what looks like a hilly ridge running between Kassel and Hof.
1) Would this possibly be the most fun ride to get there (disregarding a strenuous detour along the German Alps)?

Once in Czechia I'm hoping to reach the Slovakian - Ukrainian border via the foothills of the mountain ranges running along the north of Czechia and Slovakia, or at least avoid some of the steeper climbs (not a fan of great heights but usually a necessary evil to get to the twistier paths).

During three earlier bike trips I've ventured into Spain via France using Google maps as guidance across mountain ranges to the routes recommended in "Great Motorcycle Tours of Europe" while explicitly avoiding highways but often times it would lead me over plain provincial roads. Is the subscription to the iPhone app "Scenic" recommended to route me away from bland roads or should I bite the bullet and purchase an Garmin Zumo XT2? (2)

On the topic of "Great Motorcycle Tours of Europe", it recommends riding north of the Czech border on the Polish side in what seems to be flatter country - Wroclaw to Krakow and then on to Poprad. Is this parallel route preferable to the Mountains just below it? (3)

Thank you for your thoughts.