Oh wow! I was just going off zeroes, and I thought THAT was a good amount. Also, minor, but there's like 30 bytes each of free space BETWEEN a lot of object maps. There's a lot of meaningless object codes in there... I wonder if these were objects that were never made? I think I found some mini drums based on their codes and pointer in bank $35, but they crash the game. Object pointer c54b for one. Unfortunately, I have no idea why. I saw these in the $3d81cc-$3d9fff range. Probably more later, but I haven't gotten there yet.
***EDIT***
I am currently going through every byte from $3d8000-$3df1dx. I'm creating a hack where I mess with object maps and some other things. Terrain though, is NOT something I'm messing with
Thank you Giangurgolo and Simion32. Couldn't have been doing it without you. Also, currently, I'm only working in hex, so forgive my "noobiness".