I think randomized loot can add to re-playability when it's done right. If you look at a game with a majority of fixed loot, like BG2 it can lead to players deciding on the order of quests specific to their build before playing, or 'walkthrough scumming'.
Exactly, no matter what you do, someone is going to find a way to cheat or "game" the game itself be it through cheat programs, hint guides etc... A developer can not concern themselves with people who abuse those approaches or they will find themselves sitting in dark room nursing a bottle of whiskey staring intently at a loaded revolver.
