What do you mean by "file swap"? If you are referring to swapping out a hat file with, say, a different hat file - it would be completely pointless. That sort of thing only shows up on the client's side, so nobody else would know.

Forcing players to download the files temporarily every time they logged in would be a dreadful idea - I'd pity anyone with a data cap.

I've only ever heard you talk about Era protecting their files. I'm not confident that this exists the way you say it does, but maybe Era staff can shed some light on the subject. As far as I know, all the Graal apps have some sort of auto-ban triggered when you edit certain files. Could this be what you are referring to?

One last question for you - what issues do you think preventing file access will actually solve? It might make it more difficult to steal customs, but even if the files are downloaded temporarily I'm sure there would be a way to obtain them.