I'm currently working on ingame dialogs.
I think I can brute force my way through the compression.
It very little compressed and most of the text is available.
My hope is that soon, I'll be able to dump some japanese text to be translated.
I hope to be able to start doing that this week.
I think we will have enough spaces for good texts.
Up to now, I think only monsters names are short in text space.
As for the help, I will take any help offer that is available.
I never spoke with anyone fluent in japanese so everything done currently was based on previous games, web translation (and a little bit of common sense).
Most of those helping (well, didn't receive much contributions yet, but I'm sure it will come soon) are not translators, but regular people wanting to help and play.
My current "headquarter" is the Woodus forum and all the latest info and lists are on the dqmj2p.wikkii.com wiki.
For the patch, they should always be applied based on the original game, never from a patched one.
I'm unsure if the anti-piracy patch has any effect on the translation patch, as I don't have checksums to check if my "original" is the anti-piracy patched one (I doubt it).