Wilhelm II will not care about everything he said if he finds an opportunity to strengthen Germany, which is to join the British side against Russia
(Especially if France made its alliance with the Russians)
(Wilhelm himself is the one who killed his cousin when his government supported Lenin)
The German government hated Russia and tacitly supported Japan
No matter what Wilhelm said (Germany contributed to the modernization of Japan as much as Britain)
You can see them here they will do it
(They could have brought the 1807 border back during the First World War but they didn't and I don't see them going back in 1905)
Britain took care of itself first and was even ready to throw away a centuries-old alliance with Portugal for the sake of several colonies.
(The plan to divide the colonies of Portugal jointly with Germany and they were serious about them)
I can't see them gaining something (Sakhalin without Korea is to appease the British)
Japan's blood has become corrupt between them and the Russians
So they will silently protest against British Korea (they are much weaker than the British in 1905)
Central Asia As I said, the Khans in Bukhara and Khiva will be granted independence as British puppets like Afghanistan
Again, you're conflating 1914 attitudes with 1905 attitudes. The Germans may have been wary of the Russians, but Russia was yet focused on Asia and competing with the British over influence in Central Asia. Wilhelm saw pushing Russia into the Russo-Japanese War as a chance to get break the Franco-Russian Alliance (since France disapproved of Russian expansionism in Asia) or force it to exclude Britain and include Germany and to keep Russian and Austro/German interests mutually exclusive to cooperate. Russia didn't ally Britain and put that to rest until 1907, after they lost the Russo-Japanese War and got locked out of Northeast Asia. At that point, Russia and Germany had little room to compromise.
It's like saying the French were intending to execute Louis XVI in 1789. Maybe that was in some people's minds, but it wasn't fait accompli until certain events (Storming the Bastille, Flight to Varennes) transpired.
Plus, there's no guarantee Russia would be weak forever. Such a betrayal bears some similarity to that of Austria's role in the Crimean War, and that didn't work out for Austria. Such a move basically guarantees Russia remains a pro-French anti-German power for Nicky's lifetime.
Regarding Portugal, you realize that Portugal's Pink Map was in direct conflict with the Cape-Cairo ambitions London held, right? So that they had a rationale for alienating that particular second-tier ally that they didn't have a major geopolitical foe to coordinate against? And that Britain historically held no ambitions on Korea and still needed Japan to counter Russian influence in the Far East?
Also, what does "Japan's blood has become corrupt between them and the Russians" even mean? Is that racial or something?
Korea is very valuable in terms of resources (there are natural resources in the North)
Bringing the Japanese and the Russians together is out of the question after the war as bad blood has already taken place
But this simply proves the point of view that Britain is imperialism that cares about itself
So a scenario that they hand over Korea to Japan is not an option and it may become a British colony
Again, conflating attitudes anachronistically. We know now that Korea's North had mineral wealth. In 1905, those resources were being discovered and the sheer amount was yet unknown.
Ah yes, two erstwhile enemies have never allied against a shared common enemy who they perceive to threaten their interests more than the other erstwhile enemy. We'll just ignore the British and French, the Austrians and Germans, the Japanese and Germans, the Americans and the British, the Italians and the Germans, the Ottomans and the Austrians, the French and the Russians, the British and the Russians, so so forth. All of which pivoted during the second half of the 19th century or the early part of the 20th century, i.e. this time period.
Also, the British didn't take land in the Crimean War, despite pretty major commitments. They really didn't get anything at all, save screwing the Russians over. What you're claiming is like the British taking Jerusalem or the whole Levant because it's useful despite it being the flashpoint of a major war between Great Powers, not a place that Britain can defend, and would anger every party involved. The British could be incompetent at times, but they didn't conquer the largest overseas empire in the world because they were diplomatically tactless and irrationally greedy. It wasn't pinching every bit of valuable land at the expense of diplomatic relations unless they were major British interests (Fashoda and the Pink Map being prime examples). Otherwise they would've just locked everyone else out of Africa to monopolise its wealth, not agree to a partition of the continent.