Those missing event errors are actually very easy to fix, anyone can do that by editing the "CommonEvents" file. The error cause by the translator mistranslate which is code instead text, so you just need to change it back to the original.
For example that "Event name (Fire Ball) is not found", open the CommonEvents with notepad++, search for "Fire Ball" and change it to "FireBall", save the file, reopen the game and voila, it's fixed. Similar cases:
Normal Attack -> NormalAttack
Iwao (SO) -> 巖(SO)