This is one of the things I first noticed on Steemit. Good content is actually REALLY hard to find. I'm glad you posted this, because now I know about steemlookup.com ! I think this will go a long way in helping me discover the content I am looking for.
As far as my feed goes, I don't follow that many people, so I have not really noticed posts disappearing from my feed... but maybe i just have not noticed it.
RE: Question: Why do my posts "disappear" from the feeds? [Steemit]