Hi. I did all that. After getting the Motavian Ring to understand their language, I talked with all the native Motavians about Laconia and the Polymetryl, after which the guy is supposed to sell it to me, but he just doesn't. I'm *so* frustrated.
I finished the original game with Eusis, Anna, Amy and Rudolf. *IF* I get to finish it this time around, I think I'll include Hugh because his Sulfur skill can paralyze both the Dark Force and the Mother Brain, probably instead of Anna, whose skill is not that useful IMHO.
Although Nei's skill rocks, I won't revive her because its too much of a hassle for someone who can't read but a few katakana characters.