I've been thinking about Science Fiction, and what I would like to cut out from it. (Un)fortunately, someone else has already written the list that I had been thinking of, with only the choice of words being different.
I don't think that Forerunners are a terrible idea in and of themselves, I'm just sick of them through overexposure. I don't know of a Science Fiction saga that doesn't have forerunners that left artifacts around the galaxy, not one. It does have negative effects on the story as well, it lets writers break the rules at a whim because someone can always find an artifact beyond our comprehension. If another species already came and invented everything, there's little use for our protagonists to do anything with technology, which is too bad, since Science Fiction is inextricably bound together with its technology.
Personally, I don't mind hearing explosions in space, I always figured that it was the sound local to the explosion, so we're hearing the sound that the people on the ship were hearing. I do agree that strategically using soundlessness would be a great way to add atmosphere (tee-hee) to a space-based story.
Absurdly Human Aliens is a problem for television, but I don't see why video games or fully animated programs can't have non-bipedal aliens. Let's be honest, there's infinitely more variety in mammals on our one planet than in a galaxy of science fiction races. I've developed an easy system with aliens: rate how human they are in appearance from 1-10. If they're 8 or above, they're probably going to have a romantic interest with one of the human crew. Come to think of it, I don't recall a single science fiction romance between a human and exotic alien. This might seem natural until you recall "deviant" sexual activity on our planet is far more expansive than to our one species. A species that actually had the intelligence to co-operate and reciprocate romantic feelings is far more approachable than, say, a horse.