Re: CBS's "Rules of Engagement" for Star Trek Fan Films
CBS's claim to TOS designs and styles (and even TNG-VOY-DS9 designs and styles) is much weaker than DC comics, because Franchise Copyright has two parents, traditional copyright and traditional trademark, and they haven't used the TOS styles since the 1960s.
Depends on how long a lawyer would twist and turn the fact that there have been official "homage" episodes which did play with that background (Scotty, Tribbles, Mirror Akiraprise).
Right now we can count ourselves lucky that there's a voice of reason at CBS Legal who cares about the difference between free positive publicity and actual attempts to profit from something related to their IP.
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.