frekk
Scourge of St. Lawrence
We'll assume everything you say is correct (and I would argue some finer points, but let's just pretend everything you say is the truth), then your whole point is moot... because unlike Germany, France, Austria or any of the others... the HRE never evolved... the whole point of a "CIVILIZATION" is something that evolves over time and is distinct from others... the HRE is none of that... it was NEVER more then a series of treaties and pacts... it was never identifiable as a nation...
But the game isn't about nations, its about civilizations. HRE defined medieval civilization in middle Europe for the entire medieval period and lasted about a thousand years ... and it absolutely did evolve as a civilization, just not so much in the "political" category.
There's a grounds for exclusion, perhaps, on the basis of redundancy because of Germany, but I find the other arguments tend to fall flat - I really don't see excluding a large, and often influential, culture (or grouping of cultures, if you wish) just because their political organization was rather loose. On that basis, half the civs in the game can be excluded and we'll be left with a game primarily full of 17th/18th century nations starting out in 4000 BC. You won't be able to make Viking raids on Lindisfarne, dedicate a Sumerian ziggurat to the gods, or build Mayan temples in the jungle, for instance, because none of these groups were ever identifiable as a nation either - in fact, none of them were even united by treaty or any sort of political cohesion at all - and to me these are the kind of groups that come to mind even before national states when I hear of a game called "civilization".
By your own definition, if the only thing that is required to be a Civ is a one-time-only series of alliances and pacts that never evolves and has nothing to do with a national identity, then by your own qualifications, NATO, the Warsaw Pact, NAFTA and the Kyoto Accords all qualify as Civilizations... because they share pretty much all the qualifications the HRE brings to the table.
I don't know about NAFTA or the Kyoto accords, but what's wrong with including the Soviet Empire or (under some name) Western Civilization? Both of these groups are clearly civilizations, despite the fact they span several nationalities, as civilizations often do.