We can only root for "good guy"?
That is generally the idea, yes. Rules can be bent or broken from time to time, but generally they're rules because they work over and over.
Yeah... this is the case - by and large. I mean, of course there are always exceptions, but it's a safer bet to go with the unofficial rules of screen writing (as laid out by the late Blake Snyder).
I gotta say, though. It does sound intriguing, but its a tough ask even as a short story-- even if you're conveying it in the third person, how are we going to get across the emotions of the predator... it's values... it's character. I'd struggle with that (then again, I've never attempted to write anything like it.
Oddly, film might be an easier medium for the "no dialogue" (there've been caveman films with no dialogue - I'm thinking of one mental 70s one which I can't remember the name of) because the descriptors don't have to be literary like they do with a novel or short story.
Maybe the way to go is to write a treatment - that way, you don't get bogged down with having to be all literary and can just say it as it is - see how that goes?
I still recommend following the Blake Snyder Beat Sheet even for your treatment, though, as its a dead handy guide.