First off, I think it's commendable for people to make an effort to party with people regardless of language barriers. Next, sorry if I missed anyone else's comments on what I'm going to say, but I'm just going to comment on the first things that came to mind.
1. Not 'romanji', it’s 'romaji' (that can be written out with or without the long 'o'). In the game in would be much simpler to let them know you cannot read or understand kanji or hiragana, or that you would prefer using romaji.
Quote:
{Excuse me…} {Help!} {Do you need it?} {Invite to join party} {Thank you!}.
2. From what I understand, “help!” using the auto-translator translates to ‘tasukete’… which would be used in a situation where someone needs help saving their life, not help as in do you need some assistance. So essentially you’re saying {Excuse me…} {Save me!}{Do you need it?} {Invite to join party} I’m not too sure that’s the sentiment you’re trying to convey. Instead I might suggest saying {excuse me} (team up?) LVL ## - ## {Yuhtunga Jungle}, or {looking for members}, etc.
3. I wouldn’t generalize too much about Japanese. I'm half Japanese, and although I was not born in Japan many of my friends and old co-workers are from Japan. They were no less reserved than most Americans I know. Also, most if not all Japanese people I have encountered truly do love American culture. For example, some of my Nihonjin tomodachi were very into hip hop. They refused to date Japanese boys, and loved black guys instead because to them it seemed to get them closer to hip hop. Many of them are misled into thinking most black guys rap and play basketball. That in itself is an unfair generalization as well.
4. I disagree with the usage of http://www.intercom.net/user/logan1/***.htm (Japanese Dirty Words) as a reference. Japanese is a very clean language. I've seen this site before and there are many phrases that are mistranslated or exaggerated.
As I said before, it's commendable to be open-minded in trying to party with anyone regardless of language or cultural differences. Although, I think it's unfair to generalize too much. I've been in quiet Japanese parties, and I've been in talkative Japanese parties that liked to joke around during downtime. Same can be said for my experiences with English speaking parties. Overall, I believe being polite to everyone is just a good rule of thumb.