I had a monstrous OPML list of SEO people from the late 90s/early 2000s that include all of the above. Unfortunately there was simply too much to follow in there and instead of paring down the list I just began to ignore a lot of it. I still have my RSS reader, but I find I can get a lot of the same off Twitter, FB, Quora, and forums as well. I use RSS still for more focused and in-depth news based on a lot of keyword filters I setup in my reader. I use the SNS stuff for more general news gathering.