1) This makes perfect business sense: Google failed to create its own social feed that would stick, so instead it's piggybacking off of a standard technology (and I'm sure it'll collect plenty of data just like it would from an actual social feed). This is what Google did in the early days with other technologies like the open web and email, and it's generally a good thing for everybody (until they enter the "extend" and "extinguish" phases later on)
2) Question as someone who's new to RSS: is there a standard URL path that a reader can use to automatically find your XML feed? I've already added RSS to my site, but right now there's just a home page link to the XML document, I'm not sure how it would be auto-discovered for such a "follow" button
Generally, you can add a <link> tag in the header, but in practice many websites forgo this or mess up the implementation, so most feed readers have custom search algorithms to try and find them.
RSS is not great but I abhorred atom with a passion back when I was working with feeds. It was a way overcomplicated xml mess. RSS is so much simpler to work with, you just have to deal with less than stellar documentation.
My impression was the opposite: RSS had so many warts and inconsistencies that you needed complex heuristics & a big test suite to handle things like encodings, relative links, and extensions whereas a single XML parse was all I needed for Atom. The authors had clearly learned the lessons from the early feed producer/consumer projects and tried to avoid making similar problems.
I have no horse in this race (I don't even know what Atom is tbh; I'm inferring that it's some kind of refined subset and/or extension of the RSS spec), and I'd prefer my site to be accessible to as many readers as possible.
But do you ever saw newer version that is simpler ? :) With less features or not-backward-compatible or without mechanism for plugging developed in future extensions...
Making complicate protocol simpler require process equivalent to rewrite in software. Re-architecture the basics. It is more then seldom to the point you can think all that complications are intentional.
One example of simplification that happen in IT is UTF-8. But it was more a replacement and big companies didn't switch anyway...
2) Question as someone who's new to RSS: is there a standard URL path that a reader can use to automatically find your XML feed? I've already added RSS to my site, but right now there's just a home page link to the XML document, I'm not sure how it would be auto-discovered for such a "follow" button