You may also find useful this other schematic, which I find
easier to read, though some of the design details differ. It's from
the NesDev wiki which is a fount of useful technical
information about older Nintendo consoles.
All of the chips you mention are low-level interface logic, and
probably not important for your emulation. You'll need to do the same
The NES game Gimmick! uses self modifying code as part of its anti-piracy check failure response. 96 bytes are decrypted while being copied from ROM to RAM and then jumped to. This is to hide a routine that halts the game and displays the message BLACK HOLE when certain conditions are met.