I'm always afraid of using the RIP too, and always saw it as for spam, trolls, etc.
I too have seen an awful lot of double (or so) posting and it makes me nutso. (And gets very confusing.) If you tell me I can report these, then don't get upset with me when I do.
So this means I also report when I feel something is in a wrong category? Other than the obvious, what are some examples of stuff we can use this for?