As for the listed scenarios, I think the Moors conquering the Franks would be the worst, as the west as we know it would be stillborn. While I don't doubt that Islamic civilization was capable of even greater advances than OTL, The Moors conquering France will make it a marginal, war-ridden frontier province of a greater Moorish empire and not the center of European civilization that we know and love.
Not necessarily.
Germany in AD732 was still half Pagan. Even in the bits nominally converted, Christianity was still often only skin deep. So if France falls to Islam, most Germans will probably convert to it over the course of time. Beyond that, Scandinavians and Slavs are still almost entirely Heathen, so it will be a similar story for them. A Moslem France will still be in the heart of a Moslem Western Europe.