Glad to see you have returned to rom hacking, fireworks
In my opinion I wouldn't change a thing, the tiles are nice and so are the battle backgrounds.
But you said if you go with fire red tiles it will speed up progress, does that mean you have lost all the data to the original ceil? In that case you better off just using fire red tiles and inserting a few matching tiles to change things up a little cause really the original fire red tiles by themself are just boring, we have seen them so many times. Anyway good luck and get some fresh details into the first post