This is not surpriseing, as it was the same in FFXI, you knew if you hit a JP party, u hit jackpot when it came to content or exp grinding.
Only mistake new MMO's have these days, is not makeing mix servers, but then again i dont blame them for inplementing it, since out of 6 years in ffxi i start to understand why the JP people want peace and be able to play with people who show same respect as themself.

I startet on a EU server myself cause of some friends, otherwise i would had done the same and start on a JP server, just cause i know how alot of them are mentally compared to some others...

That said keep in mind not all NA people are ignorant bastard who see themself above evryone else, nor Europeans for that matter.
But i must say can i avoid americans i would do it anytime any day, i had my share with how the majority of them where in FFXI.
But OP this wont change for a lifetime, JP people are raise diffrently, see life in another way.

Had long talks with alot of them, why they tend to be so friendly and helpfull to people beeing complete A-holes to them, mostly is there culture " keep in mind not all JP are friendly lol, all countries have there share of idiots"
But from most of them, i got more or less same response, they are raiset to try help people if they can, even it dosent benefit them or please them to do so, that's why you see most of them do something if you ask them.

RL story from ffxi.
Was lvling my carpenter up, and there was this lovely fishing rod, callt lu'shangs fishing rod wich where beast to lvl with, since lvling in ffxi took ages when it came to crafting, and if you broke your craft you useally tend to lose all your items, but the love about this Lu' shang rod was, even if the craft broke, you could not lose it, so you could pretty much start repairing a broken Lu'shang rod at a very early lvl, knowing it would fail but give you alot skill up, now the sad part was at that time where i bought it, i had probally grindet for almost a year to afford it so expensive it was, a few hours evryday.
So you can imagen how static i was once i got my hands on it, after getting it and haveing stars in my eyes, i went on the ferry from selbina to where all the people where fishing, in hope someone would break there Lu'shang fishing rod so i could trade mine with theres.
Lucky for me after 20min wait someone did.
sadly ffxi had 1 flaw, if someone tried to cast spells on you pre crafting your item, it would sometimes break the craft immiedatly and make you lose evrything before the craft even startet.
This Paladin NA saw i was shouting for a broken one, and pretty much campet me on the boat in the background, once i was about to do it, he stood with his friend and as soon they saw me start my crafting they healet the hell out me as much they could.
Mission succed for those 2, and i manage to lose something i had workt for, for about 1 year.
To my surprise all i got in whispers, was HAHAHA OWNED NOOB, etc.
So i put in a ticket to the GM's, saying what happend and told them to read chat since this wasent and accident but very intendet, but all i got back was sorry we cant do anything about it.
So i was pretty down, and pretty much felt like uninstalling after loseing all my money on that thing, i tho would be bullet proof " yes my own bad for not crafting in my mog house where i am safe, but sometimes you just dont expect the wourse of people"
So just as i where about to log out, a JP tarutaru walks over to me and trade, beeing a bit confused i just presst ok, and he put in a brand new Lu'shang rod.
I told him no no i cant take it, and with the poor english he could, he said yes please, following up with, please nice evryone help all, no do paladin other, and logt off.
Think i scoutet for this tarutaru like 2 months evryday and never saw him online again.