That's complete nonsense. If the lens is a 35mm, it's always a 35mm - are we still having this discussion after all these years? APS-C is essentially the same size as super 35. If you want to talk equivalent field of view for cinematography, at least define it in terms of a motion picture standard. Your 35mm lens is a 24mm equivalent on your 0.7x crop "full frame" 5D.
For this sort of work, those are exactly the sort of cameras you want to be using. It's a much better workflow for doc-style work, and the cameras are much more ergonomic and versatile. Plus, they're just so much faster to use - every setting you could ever want to change is at your fingertips, you don't ever have to change lenses (barring any special circumstances), and because of the smaller sensor, you don't have to deal with razor thin DoF if you're trying to shoot in low light. And I have to disagree with you on image quality - just take a look at Mythbusters, which has been looking fantastic in recent years. Or Top Gear, arguably one of the most beautiful 'non-scripted' shows on TV - which was shot on ENG cameras.
I propose we refer to plastic pegs as C47-M's, for melty.
Not in terms of light transmission, but in terms of depth of field, it depends on how you think of it. If you consider a 24mm f5.6 lens on FF, you get a roughly equivalent field of view and depth of field from a 12mm f2.8 lens on a M43 camera. But, this change in DoF is because you're using a wider lens - not because of the sensor size. Remember, both aperture and focal length have an effect on DoF. If you take an image on a full frame camera with a 22mm f2.8 lens and crop out the middle, you'd get exactly the same image as you'd get from that same lens on a M43 camera.