I've been using http://theoldreader.com ever since. As the name implies, it does a pretty good job of mimicking Google Reader.
I totally forgot Google Reader would store feeds forever, so you could search back in time. That was actually an amazing feature.
I'm not sure what their policy on read posts is. I'm a premium user and a quick search shows up a (read, but not liked or shared) post from 2011. It says here that liked and shared posts are stored forever:
https://theoldreader.uservoice.com/knowledgebase/articles/14...
Someone at the time of Reader's demise recommended Selfoss, and I've been running it ever since. It's not quite as good, but it does what I wanted from Reader.
[1] http://blog.theoldreader.com/post/113273709664/sponsor-the-o...