What makes the NPC Bendu Olo, editor ID Player, playable? There are 1600 scripts in game which directly interact with him, so obviously I'm not going through them all to find out, but I would like to know. Also, if his editor ID and another NPCs were switched, would they become the playable character? I don't plan on testing that one because I hate crashing my computer.

On an unrelated note, what would happen if a script used disable on the player?

The player is hardcoded (as you can see when opening the CS, he is the only NPC that is there even before you load anything). You can't make another NPC become the player, which would be pointless anyway since the player's race, look, stats etc aren't fixed and are governed by other parts of the game like playable races, class, level, facegen etc etc.

Disabling the player will crash the game.