Is there any guarantee Russia sells Alaska at all ITTL? What if they decide to hold on to it for geopolitical power projecting purposes?
Agree re: Philippines - it would be the crown jewel of the German colonies, if Germany adopted the strategy of Global Empire.
Wouldn't Cape to Cairo be possible if it was a multi-nation venture under Britain, Portugal, and Turkey, with all three countries profiting from the venture?
Ironically, US commercial interests doubling down on Japan helps it long-term - it could become an economic powerhouse sooner and to greater extent than OTL. Tying oneself to the US at this point is a very good bet, though few will realize that at the time. Japan also has Korea and Taiwan, presumably (but with little chance to gain anything else), so it has some space to protect itself outside of the Home Islands but without so much that military influence grows out of control like OTL.
In regards to Italy, I could see the country having even more emigration than OTL, meaning that Italians might be more influential in the Western Hemisphere. Butterflies, butterflies, butterflies...
The reasons Russia sold Alaska, as far as I can tell, still seem to be there (Total indefensability from a hostile Britain, it being an underdeveloped and tapped out of furs money sink, already having more empty wasteland than they knew what to do with, ect.) They're barely in a better position to make use of it that the Germans, and selling it off to the Americans at the very least keeps it out of British hands, who from Canada could develop it into a knife pointed at Russia's Pacific basin.
Indeed, if they take that approach... though now that I mull it over getting a Pro-German Spain dosen't require too much thought even if it does require a bit of luck(?) for Germany. Have Prince Leopold Hohenzollern-Sigmaringen decide to spend one of his summer vactions in Barcelonia and have him fall in love with the place, to the point that he happily accepts the offer of the Spainish Throne and easing Bismark's initiative to get King (Later Kaiser) Whilhelm I to allow it. The German government gets a little more intransigent about French opposition to the affair, harsh words are exchanged, offers to mediate by Britain are turned down (Perhaps with the intention of offering the throne to a Bavarian as a compromise) finally convincing them that Bismark is a "bad faith" actor intent on fully unifying Germany and disrupting the balance of power (With his ultimate goal so close at hand, he plays more aggressive and less tactfully than usual in the affair) until in the anger something goes off and triggers the Franco-Prussian war. Since Leopold never rejects the offer of the throne, the Cortes duely elects him post-war and France is in not position to resist, with Prussia now in a position to proclaim the
Reich (Strong-arming in the southern German states much to Austria's distress).
In such an environment, in which Austria feels threatened by Germany and the Germans gain a few more Infamy points for adding the Humiliate and Take State Wargoals without the approperate Casus Belli (To use a Victoria 2 reference), I could see them turning to France as a natural check to potential Prussian expansionism and reaching a detante with the Ottomans in order to limit their vulnerability. Britain, trying to contain the new German state in its usual attempt to prevent a single hegemon from dominating the continent (And thus able to focus the bulk of their attention on expansion outside Europe... into Britain's interests) would try to smooth this along diplomatically so she dosen't have to commit her own resources to keeping the situation in Europe set up in her favor (Especially heading off a potential Austro-Russian alliance; Austria's only viable alternative to check Germany without France, which would mean Britain now has to be willing to risk a major war if she wants to keep her rival in The Great Game out of the Balkans and bottled up navally in the Black Sea). Faced with that potential for otherwise being isolated diplomatically, Russia and Germany would then naturally gravitate towards one another, and would have a German friendly Spain (German monarch, plus likely more sympathy towards them than the French from the Cortes, who would interpret the events of the Succession Crisis as France not respecting her sovereignty). This would create the right diplomatic conditions for the proposed alliance structure without running the risk of overly affecting key events in the early to mid 1800's. Granted, you probably butterfly away or at least result in a far more Pro-Turkish Congress of Berlin (Since the conditions that would result in the Russo-Turkish War of 1877 with the Ottomans fighting alone are hardly the case here, with British and French backing and a sympathetic Austria).
On Japan's grounds... I don't think it'd exactly be them choosing to align with the US. My guess is it'd be a bit more like Hawaii; the dominance of US commerce would result in greater American influence in their politics, and domestic industry could very well find its growth retarded due to competition with American imports (Who, of course, won't get tariffs slapped on them) and pressures from bussiness representatives who don't want to see their potential customers becoming competition themselves to the imported goods. We're not nearly at the point yet that labor cost in the US is going to be a factor in jobs getting outsourced to East Asia (This is the time of Sinclair's
The Jungle, after all. Indeed, cheap Italian labor making another immigrant wave might even drive down labor costs a tiny bit more if its leans too much on the US... or maybe they help out Argentina). I think Korea could be interesting though; if American commerce tries to "jump off" from Japan there only to start bumping up against Russian interests in Manchuria.
(Wow... this setting is flowing really easily to me.)