The tradition is both older and newer than this. As an example, in 1602 Samuel Rowlands produced a pamphlet poem Tis Merrie when Gossips meete, which included the verse
Well wot you Besse, to whom Ile drinke too now,
Sure as I liue, vnto your sister Sisse,
And to the Youth that did the Angell bow.
And sent it for a token : trueth halfe ...
The Entente allies did cooperate and coordinate. But on a much smaller scale than in a later war and even much much less so with Russia. Among the Western powers a Supreme War Council (SWC) emerged over time. But it was only founded in 1917, after the Russian Revolution. With Russia the exchanges were minute in comparison. Diplomatic channels were used ...
In WW1 Russia was formally a member of the Entente, while during WW2 the Soviet Union was cooperating with the Allies more because of a common enemy. A good example of the coordination between the members of the Entente is the year 1916: as the battle of Verdun unfolded and proved to be very costly to the French army, the British launched the Somme offensive ...
No. At least not in the "early" going.
My father was born in Hong Kong in 1923, and he still remembers signs on public buildings that read, "Dogs and Chinese not allowed."
The British wanted to avoid every possible contact with the locals (except as "servants.")