You know, you're right. Since Wilhelm Wilhelm was overthrown any restoration would be able to define his powers because even he should have known that he was certainly not in a possition to bargain. I suppose a man like Richtofen and other aristocratic conservative types might want to reinstate him. Maybe the title could be downgraded to "king" so he doesn't forget that the rules have changed.
Though we might like to tell ourselves otherwise, this is clearly very true.
While nationalists in most countries in Europe were very anti-semitic, the German variety had the potential to be especially dangerous for it was motivated not merely by blind hate and suspicion but was also an integral part of a kind of German nationalism that was popular among quite a number of "intellectuals". One of the most notorious of these people was Wagner.
Still, it is unlikely that the government in this TL would be so obsessed with this ideology. Sure, there would be anti-semitism among the leaders but being more conservative military men, they would probably have felt that they had more better things to do than obsess over the Jews. Fringe radical parties who maintained Hitler-like ideology would be a threat the new government and their activity would probably be suppressed along with other troublesome political competition.