I have a system almost fully working; I'll be releasing it by Tuesday hopefully. Mithran, the game's input is definitely tied to the Keyboard messages via the OS to the window, and I can setup a callback to inhibit that. To create said callback, I've built up from Wanabe's LoadSo project,
found here, and have re-implemented the Ruby C API; a couple of the original .so files can be loaded in, but not all of them. The project is still being worked on, but I have it working enough to load my own extension in, one that sets a keyboard hook and disables F1, F12, and Alt + Enter. Actually, the dev can disable any key combo they so wish by adding it to a global array, although I might hide this array and just make functions to add / remove the combos.
All this can be done from a simple DLL that can be used via Win32API, but I want to revitalize Wanabe's project and progress it further, so that JSON, XML parsers, YAML, etc can be used in RPG Maker as well.
Edit: Sorry for the uproot Dekita, I just wanted to explain a bit further. <_<