To be honest, I haven't thought about those pages specifically, only an overall approach. When I made the filters I didn't really anticipate your point that higher reputation doesn't often equal better quality on those pages. I was operating under a general principle that higher rep content is on average likely to be better than lower rep content. I'd have to think about it some more, and I'd need to find out exactly how reputation is calculated (apologies if you already mentioned it in your post; I'm so busy coding I have to skim read long posts). Do the extra votes that these common accounts get by constantly being on the trending page contribute to their higher rep? If so, without any qualifiers, the rep system might need reworking (or an alternative concurrent system implemented). This will have to be a project for another day for me. My head is esploding with other projects at the moment ;). I wish you luck, though, in getting Steemit to implement some change. Hopefully an upgraded UI is coming in the not too distant future.
RE: Proposed new section/method for seggregating posts starting with the trending page