I remember once finding the text routine (in original non-dx), but I don't have it in my notes. Everything in the game runs on counters, that are incremented each frame. Then at say, 10th frame the counter is reset and the next character is copied to the spritesheet. It's probably not that hard to change once you find the right 'update' routine (I expect that text is just another type of object like enemies, but don't remember for sure). I could find the object id in debugger once I have a bit more free time. With the id just look up the address in a giant jump table and you get the right routine.
As for the Oracles - they have totally different engine, just reuse the graphics. There are some similarities in code 'style' (probably from the Nintendo SDK, although it's totally different from Pokemon 'style'), but it looks like Capcom didn't reuse any of the LA code.