Please, to compare a complete remake of a game to fanfiction or remixes is ludicrous...
For one, most remixes are just that, remixes, they aren't trying to remake the compositions...and, if nothing else, that's just the musical side...
As for fanfics...they're nothing but jibberish mostly, I personally think they should shut down the Novelization project...But most of it isn't a retelling of Chrono Trigger...Besides that, trying to shut down fanfics would be like trying to shut down people's blogs...
A game remake encompasses music and scripting violations. It's not the same when compared to those entities seperately, no.