Yes. It's how I browse HN.

Rss for articles +25 points to Pushover onto my phone.

Yes

I see bots trying to generate feeds in my access logs. Some of them are coded very poorly, ignore cache-controls, re-check articles every 30 seconds indefinitely. So it would seem they are still used. daily-digest/1.0 (Article Reader) is the worst one I have seen thus far.

Yes

Yes. I just debugged problems with our RSS feed at work. I have my own intelligent RSS reader called YOShInOn which learns my preferences.

Every day. Who doesn’t?