Good job on turning your thoughts into a post, and thanks for the mention of Looking For Niche!

I am all for increasing discoverability and personalization. Favoriting content would definitely be easier than having to bookmark on a browser level, and letting others see your favorites, sort of like Twitter, is also a neat idea. At the same time, it is a way to learn more about your Steemians interests.

It's a bit harder having Steemit resurface older posts. Steemit is based on the community curating everything, so I don't know how "good old posts" should be determined. I think your problem is better solved with a mix of your #1 and #2 suggestion of personalizing the trending page, sort of like you would personalize a Facebook feed. You would still miss old posts, but you would on the other hand be more likely to see them in the first place, if uninteresting (to you) content didn't clutter your feed.

Being able to have people share curated community feeds natively in Steemit is something like what I have been looking for

I vouche for things that can help out niches here on Steemit, hence why I created Looking For Niche. I think Steemit has great potentiel to be the go to "blog" service for everyone, if/when more discoverability and community features are implemented.