No, any command that is not white listed in the official rules forum post are not allowed. You are allowed to manually change to a more preferable FOV in the settings menu before your run, but changing it using a key bind during/ before a run is not allowed (I'm pretty sure), since it is not white listed . What i'm not sure about is why you would want to have a key bind to change FOV in the first place, but to each their own I guess :)
default_fov is cheat-protected fov isn't cheat-protected
Obviously any cheat-protected command is banned, therefore, it's banned.
I believe there is a slider for fov in the advanced tab in the settings menu, I'm not at my computer right now so I can't check
As of today, 17/03/25, ghost door is officially banned in all runs, due to it not being possible without pre run setup (if a setup is found from game launch the rules will be updated accordingly). All previous full runs utilizing it will be grandfathered in, and all previous ILs utilizing it will be