Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
Possibly. It really depends on whether it will overtake your personal settings folder and more importantly, whether it alters that data such that 1.5.0.7 doesn't recognize it anymore. I would recommend backing up your preference data before you install the RC.