Hello second developer!
I did not get a chance to document much so please forgive me.

1- Mode 7: If you don't wanna use mode7 don't use mode7, but if you do basically just look at my teleport events, it might seem esoteric but it fixed
   a bunch of camera bugs.
   
2- If you're wondering how something works, just look in the event it's usually straightforward.

3- If you need missing menu options or battle options go in the scripts.

4- Understand well how "wall" works. (if you use mode7) It works with terrain tags between 1-5. 
   Basically make sure that two objects that are both different height and touching must have different terrain tags otherwise
   You will get the high object suspending from the low object, and not tied to the ground.
   Other than that mapping is straightforward. Can't do sidewalls, sorry.