A victorious Germany intervening to stop the Soviets is probably the most plausible bit of the scenario and I agree with you re Italy.
I have to disagree. As I understand it the Germans and Soviets were sometimes pragmatic collaborators, while the Whites were fanatically anti-German to a self-defeating degree.
That said the White victory should still be kept, it's not Kaiserreich without it, and you can justify a White victory without a German intervention.
I'd axe the Papal States and Two Sicilies, giving their lands to the SRI, but leave the Republic as an Austrian puppet and Sardinia as Savoyard Taiwan.
Also on the subject of a Kaiserreich Italy wishlist, I'd make the ANI not anti-Austria anymore. I know fascists aren't known for making incredibly sound strategic decisions, but blowing up relations with the only power backing you up against the syndie revanchists for the sake of Trieste and a slice of the Alps is a whole new ballpark of stupid.