Germany has no historical events in EU2, as it didn't even exist at any point from 1419-1819. Bohemia, on the other hand, does have a few events/leader (but none after 1528 or so). Basically, I think we should either find a way to set up historical events for nations that wouldn't have any past certain early dates (Hungary, Byzantium, Burgundy, Italy, Norway, Bohemia). Obviously one solution is what KOM said above:
Norway-->Denmark or Sweden
Burgundy-->Netherlands (or start them as Burgundy and then later change to Holland)
Italy-->Venice(?)
Bohemia-->Austria or Bavaria
Hungary-->Hungary or Austria
Byzantium-->Ottoman Empire
The biggest problem with this is Byzantium switching to OE, as if we kept it Orthodox it would massively conflict with historical events. However, if we switch it to Muslim, all the lands it rules will be the wrong religion (Orthodox). These are big problems here.
Alternatively, we could import historical events from AGC-EEP, Abberation, and other projects (maybe make a few of our own) for nations like Byzantium, Italy, and Hungary (nations that have no clear country to change to).