Hardly the same level as Imperial Japan or most of the other major powers of the day.
A few border clashes and small expansion into neighbouring lands isn't quite the same as trying to conquer all of Asia and a large part of the Pacific.
This is probably a more plausible ATL then having China trying to conquer India or being a straight swap for OTL Japan's aggression.
True enough on both counts, but don't expect Russia to just let Britain and China have their way. It could also lead to Russo-German rapprochement, as Kaiser Wilhelm II was the one behind the Yellow Peril IIRC, and with Japan a Russian satellite/protectorate and thus effectively 'tamed', his antipathy would turn against the resurgent Chinese. His government might also back pro-Russian sentiment, if only because in this scenario it focuses Russia's attentions away from Europe and the Middle East to the Far East, something that the German government would welcome, given their interest in the Middle East (Berlin-Baghdad anyone).
If Germany allies with or even just stays friendly with Russia, then a WWI-equivalent in Europe is likely to favor Germany and Russia. The British blockade is meaningless, Germany will just import ore and food from Russia and crush France and Belgium in a matter of months or even weeks. The Middle East and the Far East are more iffy, but I'm sure if the Soviet Union could effectively project power in the Far East via one railroad, the Germans could do the same via Berlin-Baghdad. They'd probably split up the region between them, Persia to the Russians, and Mesopotamia to the Germans. Not sure for Syria or Palestine, I get the feeling the Germans and the Russians will want to stay out of the Royal Navy's gunnery range, which could prove problematic along the shores of the Persian Gulf. In the interior though, the German Army (not sure about the Russians) would probably trump the British Army in the Middle East.
In the Far East...eh, this one I'm definitely not very sure. On one hand...yeah, the Royal Navy is
the premier navy in the world, but...yeah...the Grand Fleet will have to stay at home to deter the German High Seas Fleet and the Russian Baltic Fleet, and priority for other first-rate units will probably be the Mediterranean and the Persian Gulf. Between the Russian Pacific Fleet and the German Far Eastern Squadron, plus the allied Imperial Japanese Navy...hmm...I'm not sure, but I get the feeling while the Germans would lose their colonies in the region the Far Eastern Squadron could retreat to Japan and/or Russia, together dominate the waters around Korea, Japan, Manchuria, and the Russian Far East. On land though...well, the Chinese will probably have British assistance, but the Russians will have German assistance, and until the IJN and the Russian and German naval forces are knocked out, they can't attack the Japanese Home Islands. Outer Manchuria could probably be contested by existing Russian forces in the region (I personally find it unlikely that Russia would not build up its forces in the Far East with a resurgent China sitting on its border) and Vladivostok would probably be impregnable with battleships in port ready to bombard anyone stupid enough to try and come close, all the while building up forces/reinforcements before launching a counterattack to drive the Chinese back into and out of Manchuria, and probably sending forces into Korea (possibly with Japanese aid depending on how much focus the Japanese gave to their navy as opposed to the army).
Depending on how things go...I can see
status quo ante bellum with regard to the Russo-Chinese border, with Korea maybe a treaty-neutral nation. Japan might take Formosa at last, but that would also depend on how things go at sea. Not so sure myself about the Middle East or the Western Front though, as while the Russian Army is good against the Chinese, not so sure vs the British, though the German Army would probably hold out. Another problem is that no way in hell Britain would let Germany build its coveted Central African Empire, which could prove a major sticking point in peace negotiations.
If they still go revolutionary in the early 20th, more or less on schedule, depending on how well China is industrializing, perhaps China could take advantage. Mongolia might not even slip away in this version of history, if China has more weight to throw around (of course, then we’re dealing with the question of how the Chinese revolution goes), and China might be able to reverse the Amur acquisitions.
Not sure about the Russian Revolution breaking out, as the effects of a Chinese victory in the Sino-Japanese War could butterfly a lot of factors that led to said revolution. Even if my two cents on an ATL WWI above are off, I still think a resurgent China allying with Britain and heating up the Great Game could very well lead to Russo-German rapprochement, with Germany helping modernize Russia in terms of both industry and the military. German economic influence in Russia could also have political influence, maybe even the Tsar allowing for a German-style constitution.
Yes, very OOC for Nicky to do so, but I think he could be convinced that the Duma could be kept under his thumb, as under the Imperial German system, even with universal male suffrage the system is rigged in favor of the conservative factions of society, and of course, the Prime Minister/Chancellor is responsible not to Parliament but to the Emperor. Yes, I know it's more complicated than that, and that the Reichstag eventually proved capable of asserting itself, but that wasn't the case when it started out, and Nicky might be influenced enough to think he could keep the Duma down indefinitely.
(shrugs)
Stranger things have happened; I imagine if you told a European in 1900 that by 1918 the German, Austro-Hungarian, Russian, and Ottoman Empires had collapsed after being bled out in a four-year war, and that the British Empire was on the brink of bankruptcy, all because an Austrian Archduke had been assassinated by a Serbian terrorist, you'd be carted off to the loony bin.