1- Mostly programming bloggers whom I am reading from for the last decade or so. Occasionally, I add stuff like Low Tech Magazine and continue them if they have semi-regular and decent content.

2- QuiteRSS

3- None.

4- Provide a nagging comment on the HN/Reddit article to provide a feed. I get they wouldn't want to, but still I try to make my case.

5- Absolutely, now more than ever. IMHO, I realized that if I could keep curating my feeds somewhat regularly, then I could actually lay off proggit and even HN.