Graphical glitches on overworld map while walking

I'm familiar with hex editing (I've done things with other games before) I'm just trying to learn what I can and can't accomplish without doing it, since it is a bit of a pain.

I can't run sleepydude's editor that's why sometimes I have to change an exit manually (like I did it for my WOB Colosseum). It's a bit of a pain because you have to calculate where exactly is your exit in the ROM, even if you know where the exit data is.

I also use editors for a lot of changes, such as monster stats, graphics and AI but sometime the only tool available is an hex editor, especially when it comes to event editing/creation or assembly hacking.