I made an account here after playing through the demo, so I could say how great the demo came along.
I found some of the maps to use a few incomplete tilesets, such as the snow forest in magus's chapter, and a few tiles fell on the wrong layer like in the Deandorino Mts.
Also, with all of the inaccessable places that freeze your game, it might help to just put an NPC event right at the entrances of those places to stop people from having to reset.
Dalton's hideout was a good idea, but you should make all of the entrances teleport events so that you can't cheat by just sticking the hero through the entrance to see if it's the right one. More rooms would be cool, too; and I suggest some more small battles in those rooms to make it feel like a full-on dungeon.
Saving Scala was a good idea to wrap up Magus's loose ends, and I could tell you obviously have plans for her. Just don't make her a clone of Magus and we'll all be happy. xD
I played the demo on a new game plus of maxed out characters, and I noticed that Chrono's Rainbow(AKA the "Death Wish" I think..) was a fist icon instead of a sword. Big letdown when I went to fight expecting chrono to use his bare hands. xD
I found most of the museum artifacts, and I find it to be a cool idea to have this be integrated throughout the game to have players go through an old dungeon again or to have an excuse to talk to all of the town NPCs.
Story-wise, I love the how you turn Porre and Guardia against eachother; it's a whole tangent off of most of the original CT storyline by going a litte political than usual. Be careful not to make the game way too wordy because of this though. The original CT story was great because the story was a little generalized to leave a lot to our imaginations.
One complaint of mine is the end of time. There is no reason for it to be abandoned since it will always exist no matter what. Even if Gaspar is gone, I think you should still have it be an accessable place.
Oh, and when you get an instrument out of a chest (either at the singing mountain or zeal palace ruins) it says "you recieved an Lnstrument!" or something like that. xD
Other than that, just poslish up here and there on your mappings and other small stuff and you have a great game in the works.