Personally I see the value in what you are proposing. It's just a matter of making hash tables easier to use. I don't personally subscribe to the opinion that anything that can be scripted easily should not be implemented directly into mIRC.
Regarding the error message: I think the main reason for opposition to that is because of calling it an "error". I wouldn't call it an error -- it's just a notification that the file was created because it didn't exist. It's like if you use /write with a file that doesn't exist, that doesn't give you an error. It just automatically creates the file for you.
