The title screen was created by JCE3000GT, actually. It's one thing I don't really know how to change on my own, so that'll stay, at least until my interests turn toward actually figuring that out.
That's a good suggestion about the keys in Agart. "Fithos Lusec Wecos Vinosec" is a reference to FFVIII, (that's what the choir is chanting in the Sorceress's theme music) but I imagine even people who have played that game might not get the reference (or know that). And that should be pretty easy to change/fix.
I kinda like the sea shanty. I'm certainly no composer, though. If someone came to me with a Midi of an original piece to use instead, I would certainly give it strong consideration. Programming new songs into FFIV is REALLY HARD, though. To my knowledge, I'm really the only one who's done it. I created a how-to doc that I meant to publish here, but haven't yet. The choice of instruments is pretty limited, too - that there might be a softer brass is a pipe dream. As a matter of fact, the "tuba" baseline and the "trumpet" melody are the same instrument in different octaves. The choices are pretty much brass, harp, guitar, piano, organ, wind (flute), synthetic tone (like, computer beep), cymbal, drum and whistle (like a gym teacher's whistle, used at the beginning of the black chocobo music).
The idea behind hiring is that the player will be allowed some variety in the "final" party (some of the permanent characters will be swappable as well). Did the demo I linked you have the part afterwards that allows you to try out all the playable characters? The game's engine doesn't really support unrestricted party changing, so hired help (inspired by FF Tactics) was a way to allow variety while still having it make sense that a character's experience and equipment is lost forever if they leave.
Regarding the dialogue, FFIIUS definitely had its translation problems (as did all Final Fantasy titles through FFVIII). My goal was to keep the JRPG feel, as well as any existing characterization (for the characters that carry over from the original and The After Years), but also make the dialogue, well, good. There will be more intentional humor than the original, plus some noticeable nods to longtime FF fans.
Aside from the title screen, this is pretty much all my work. I am of course using tools (mostly FF4kster) created by other people, but a significant amount of the hacking still needs to be done manually. I might want to get an experienced/talented spriter involved if possible. And maybe someone to compose some original music, though I can safely reuse much of the original music, since the game exists in an established universe. But, yeah, that's why fresh playtesting opinions are so valuable to me, so... Thanks!