I don't think the the converter is questionable legally in the slightest bit. It simple reads Marshaled Ruby data, and Enterbrain has no rights over Ruby. Just because something is free doesn't mean you can distribute someone else's intellectual property with it.
The fact that it is free would likely eliminate anybody from actually caring, though, since they can be found publicly anyway, so I suppose it shouldn't pose that big of an issue. Since we are making no profit from it, I imagine the worse case scenario is we are ordered to quit distributing it with them, so screw it I guess, lets use your idea.
As for graphic and audio resources, I say we distribute nothing, though it matters little to me. It might be nice to have ARCs true full release come with the new RTP, and it still be new and fresh.
EDIT:
Oh yes, and about the Pony topic:
I did that from my phone. I had read the topic earlier, and was returning to respond, and my fat finger must have pressed the wrong icon.