Slash: Characters who are established as gay or bisexual, characters who are alleged to be gay or bisexual, and characters whose sexualities have not yet been explored may be slashed. Those are the current rules. The moot will be called to decide the permanent slash guidelines in a few months
Flames will be sacrificed to R'hllor. Inappropriate behavior will be cause for those responsible to be sent Beyond the Wall (aka bannination). By inappropriate behavior, I of course mean wankery and rudeness. Courtesy is your armor, and without armor you're weak. The weak get handed to Ser Gregor Clegane. Savvy?
Negative discussion of the books will be allowed at the mods' discretion. I do suggest you keep it polite. View the mods as your friendly neighborhood Dragons. See above on what happens to impolite people.