Well, I figured I'd update to let you people in on what's going down. What I've been doing for the last 2 or 3 days is writing a GM project reader | writer for different versions of GM. Specifically 5.3 on up. Now, I have done this for GMare before, but I never added support for anything but GM 6. So, it's alot more work, and thus is the reason it's taking so long. As of right now the program can read the supported GM project file versions. However, the last thing I need to tackle is GM 7 project file's obfuscation, which is gonna be a pain in the ass, and really what I was setting out to do in the first place.
On the upside. I've decided to just keep Ocarina Room Editor just the way it is, and convert tile ids to rectangle data like GM likes, on export. The best thing about this approach is that nothing needs to change in .oref files. I got rid of the tile binary export function, but I don't know if that was a good idea. Maybe people will still want to use it.