in what way was WWII...caused by imperialist friction ie between empires for reason of empire...

It was not, because the German Empire ceased to exist at Versailles. Further, the German overseas colonies had not been particularly significant to Germany's overall military machine before and during WW I. But the goal of French diplomacy at Versailles was to render Germany incapable of reconstituting its military power, in no small part by preventing Germany from having secure access to important resources, especially oil. In addition to depriving Germany of her overseas colonies, Versailles also broke up her chief ally, The Austro-Hungarian Empire, which limited the extent to which Germany could count on oil from Romania.

Germany chafed against these conditions from the start. Then there was the occupation of the Ruhr and the hyperinflation. To get out of the box into which the French had put her at Versailles Germany needed to reconstitute her continental empire, which had been largely commercial under the Hapsburgs. The fact that the Nazis called it The Reich instead of The German Empire is largely inconsequential. Germany wanted the functional equivalence of what they had possessed prior to WW I, but wanted better control. The envisioned Thousand Year Reich was to be an empire to end all empires. Hitler hoped that the UK and US could be persuaded to accept German hegemony in Europe and Africa.

That is what I meant by referring to WW II as the echo of the old imperial conflict which Germany had lost. And it is still not inconceivable that Germany might not have succeeded with different tactics, such as not attacking the Soviet Union or Poland. Had Germany been able to seduce Hungary into an alliance and, through Hungary gained access to Romanian oil, without provoking war, who knows what might have developed. Whether this is called imperial conflict or power politics is largely irrelevant.

"It is not necessary to have hope in order to persevere."