I'm getting closer to releasing the patch, but have a few more questions for anyone familiar with recent versions of T-Edition:
- Does the Kaiser/Czar Dragon still exist in the latest release? There's a bunch of his text that I translated that I haven't come across yet in-game
- Does the "complete every pub quest" achievement work properly? I could swear I've done them all already but nothing is showing up in the achievement room
- In the Beginner's House, in the new secret area there's that room with the airship model, bone carving, talking chocobo, etc. What do I need to do to fill that room out?
- Is there any new content that I'm liable to miss? I miss the old Dragon's Den and wish it was back, but the new place is pretty cool too
- Speaking of which, is there still a secret gravestone in Eureka? I didn't see one when I explored it earlier
Going off what Raijinken/Serity said, adding my info in:
Kaiser is gone/all that text is from an earlier version of the mod I guess, and he never removed it/you pulled it off the EX patch? If you glitch out of Narshe in EX (just load a save file on EX not in Narshe, like the world map), you can explore the game but it's heavily bugged (all battles are garbage/NPCs are the wrong sprites etc due to his tampering). He seems to have used an old version of his mod for the EX patch, because if you enter Eureka, it's actually Dragon's Den, fully coded, but battles are all garbage data etc. Feel free to explore, though

All the achievements work, yup, we've had a few players show it off recently/I've personally seen every statue in the collection room. Chances are you may've missed one, it happens, especially if it's the WoB like at South Figaro before the WoR (Protect Mt. Koltz! or something).
Raijinken explained the achievement room, yeah it's mostly the auction house stuff (you can buy the airship/kappa robot etc now) and I believe the magicite is from getting all the espers. Magitek armor is from entering Kefka's Tower.
The new content you might've not seen is the new tower east of dino forest. If you haven't explored it, go check it out

it wasn't there when you played years ago. There's also the Soul Shrine north of Mobliz if you never checked that out as well. Otherwise, all the new content is listed in the new event html files and not missable (the dev room as Serity mentioned has a ton of stuff like interactions with npcs if you have specific people in your party, there's reactions to the bookshelf in the Namingway room (exit/enter to reset it) based on your party lead, and comments on the music player in the dev room/Maria comments or an NPC at the table if its an FF6 song only (there's like.... a handful of other songs as easter eggs also, try FF3 Aria the Maiden of Water and one of the Xenogears songs, Maria sings the lyrics to them if talked to).
All that "The seal of" stuff is Dragon's Den/not in the game. Defeated Cerberus! text to my knowledge isn't used either, as Eureka has a handful of FF3 bosses and none have "defeated xxxxx", it's something simple like you find an armor, click it, it says its name like "Illusionary Bracer" then the boss talks like "Defeat me and it's yours!", battle, win, "Obtained Bracer!" that's it.
Also one thing you may want to look into that we just had a player discover (and I can't notify Tsushiy yet since he's still MIA), is in new game+ if you take Relm to any inn or place you can change costumes and select her outfits, the game exits the dialogue and removes her from your party. She goes back to the airship and is fine, you can change outfits on the Falcon still, but if she's the party leader (or just in the party, it will stop the dialogue too/remove her) it gives you an invisible leader and the screen doesn't scroll correctly/can trigger the partyless party glitch if she's solo. Entering the menu/exiting with others in party just puts #2 in the lead and fixes this. I personally checked every other character, all of them can swap costumes, just it removes Relm. If you're able to look into this/fix it, definitely let me know, but I mentioned it in our read me/bug report.