Many Japanese politicians did indeed compare their actions to that of their western contemporaries. Celebrated author Yukichi Fukuzawa famously said; "We shall someday raise the national power of Japan so that not only shall we control the natives of China and India as the English do today, but we shall also possess in our hands the power to rebuke the English and to rule Asia ourselves". His views on the subject were quite popular at the time, and many shared his sentiments.
Another factor was Social Darwinism was at it's hight in Japan, and anti-western perceptions only cemented that. I do not know if Konoe actually believed that himself, but it's not impossible to believe, as many of his contemporaries did.
For the Japanese, a lot of the time leading up to World War II was spent playing "catch up" in a sense, to their European Imperial counterparts. The Meiji Restoration, which led up to the reinstitution of the Emperor of Japan as the head of government saw the beginning of the modernizing process, but certainly not the end of it.
Commodore Matthew Perry's expeditions (1852-54), in which he established trade relations with Japan catalyzed the political and economic shift towards a more open market and more centralized (less feudal) system of rule. In the time following Perry's expeditions, Japan's efforts to modernize its military and economy often came in the form of advisors from European countries such as France, Germany, Britain, and the United States which Japan saw as ideal to emulate. French-born American Charles Le Gendre, for example, prodded Japan to attempt to establish a colony in Taiwan in 1874 as a display of its imperial status. http://en.wikipedia.org/wiki/Japanese_invasion_of_Taiwan_(1874)
After World War II, when the League of Nations was formed, Japan found itself in a position where it was almost but not quite as respected as the established European powers and the United States. Repeated silencing of Japanese opinion and their impotence in the system led them ultimately to leave the League, but aspiring towards being an empire of equal stature to those of the Western World continued to be a fixation of theirs (and a necessity, given the culture of global politics during the time). For some on this, I'd check out Japan and the League of Nations. http://www.uhpress.hawaii.edu/p-4998-9780824829827.aspx
Yes. This was a common viewpoint.
Having an empire was well accepted among the more powerful nations up until the end of WWII. Japanese politicians often felt that the Anglo-American opposition to Japanese imperial expansion after WWI was a just a hypocritical attempt to maintain a monopoly on the national power derived from exploiting the "less advanced" nations. Following the logic of social Darwinism, they accepted empire as the natural state of global politics, and thought it unfair that they be denied the opportunity to secure a powerful empire that other nations had.