Well, here's most of my stuff:
I use Linkding. Imported all bookmarks from browser and added tags. Helps me find stuff later. Search is also good. My bookmark bar in the browser is now only for quickly accessing the stuff I need daily.
On android Antennapod if you want open source, podcast addict if you want total control. The latter has settings/options for everything (when to download what, fine tuneable playlists, etc.), but is not what I would call user friendly.
I don't have first hand experience, but yeah, I've read about challenges with the maintainer of TTRSS and decided on FreshRSS. Been very happy with FreshRSS for years so never tried TTRSS.
Yes. Self-hosted FreshRSS, which can pull the full articles, reading either via FreshRSS or feedme on android. I basically never visit websites if I'm not searching something specific.
Could you tell me the name of the company?