Policy 2: Regarding fanfic of the fanfic, continuations, etc. The disclaimer means something. The freedom I feel to appropriate and play with the original material applies to you as well with the result of my appropriations. If you feel like writing continuations, more stories in a particular universe variant, whatever, you may do so with my blessing.
Attribution is the only currency fans have to reward each other, so please do attribute and link to the original. (In fact, this is what the disclaimer is: attribution to the original creators of the universe.) And drop me a line so I know you've done it and you can make my day.