Then why not mention Christianity for Japan as well?

I would think it would be the other way around with Buddhism influencing the early Christians- Shakyamuni predates Jesus by a few hundred years. And if we consider the root religions, Hinduism predates Judaism by a thousand plus years, I believe.

King Ashoka was sending out Buddhist missionaries somewhere around 200 BC. Though I don't think many scholars advocate any influence on Christianity by Buddhism (or vice versa).

(1225.1) 112:0.1 THE evolutionary planets are the spheres of human origin, the initial worlds of the ascending mortal career. Urantia is your starting point; here you and your divine Thought Adjuster are joined in temporary union. You have been endowed with a perfect guide; therefore, if you will sincerely run the race of time and gain the final goal of faith, the reward of the ages shall be yours; you will be eternally united with your indwelling Adjuster. Then will begin your real life, the ascending life, to which your present mortal state is but the vestibule. Then will begin your exalted and progressive mission as finaliters in the eternity which stretches out before you. And throughout all of these successive ages and stages of evolutionary growth, there is one part of you that remains absolutely unaltered, and that is personality — permanence in the presence of change.

Yea I'm not so sure buddhism was affecting early Christian converts or disciples, Chritianity changed the face of the roman world, buddhism not so much.

Interesting segue into what my impression is so far...

Namely, putting aside any doubt I have about a paradigm that claims to have the Truth, this all seems fairly eurocentric in the Christian sort of fashion wish a dash of new-agey spiritual supermarket flavor... That is bits and pieces of other religions are thrown in to make thugs appear all encompassing.

Not to say it won't help people, could help lots ... Though it seems cobbled together to satisfy western ideals.

If that is your first impression I would have to respectfully disagree. This is only the books take on Urantian religious heritage which for the most part has been dominated by judeo christian beliefs in the West with buddhism surviving in the east. I don't believe there is any arbitrary or calculated eurocentricity within the text but there may appear to be some since Christ Michael (local universe creator) is indeed the cornerstone of Christianity which did take hold prominently in the West.

Overall the text is fair to almost everything discussed and favors christianity since it more accurately promotes true universe realities. Keep in mind that discussion of world religion is a very small part of the book comparatively and is only the tip of the iceburg that is the UB