I'm going to take what you said, and tone it down a notch: anything that sounds self-published is a ref flag for me. Whether or not it is self-published is not a huge concern for me.

I never really thought about what those red flags are, but I can tell you what I'm looking for. I am looking for an element of realism, even in genres like science fiction and fantasy. To offer an idea of what I mean: things like interstellar travels and magical creatures are okay, as long as it is there to drive a plausible story. Space battles and horny vampires are not okay, because it is mostly about the fulfillment of fantasies that stretch the imagination.

I'm looking for some sort of indication that the story is driven by the plot. Characters aren't a huge issue for me, as long as they are believable and I don't end up hating them. I do have a preference for strong characters who are led by reason rather than emotion. For some reason, I get the feeling that weak characters are having their story written for them rather than having their story written (which, again, strikes me as fantasy fulfillment).

Perhaps somewhat contradictory, I also prefer modesty from both the characters and the author. Blurbs that indicate that the characters have overgrown egos leads me to think that the author has an inflated ego or is writing some sort of fantasy fulfillment story (notice an ongoing theme here). Authors who say how great they are or how great their story is also raises red flags, since nothing is that good. Even if it was getting close to being that good, it is the place for independent reviewers to say so, and not for an author to tout their horn.

Oh, and the blurb should be written in a style that I can appreciate. Factual about the story itself. Variation in sentence structure. The tone should reflect the story rather than a sales pitch. I shouldn't be gasping from reading run-on sentences, nor feel like a hyperactive chipmunk that can only blurt six words at a time (i.e. short and choppy sentences).